{"segment":[{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["3"],["5"],["10"],["4"],["22"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":" <span class='basic_left'> Ng\u01b0\u1eddi ta th\u1ed1ng k\u00ea s\u1ed1 chim b\u1ed3 c\u00e2u c\u1ee7a c\u00e1c chu\u1ed3ng trong m\u1ed9t trang tr\u1ea1i ch\u0103n nu\u00f4i r\u1ed3i l\u1eadp b\u1ea3ng \u201ct\u1ea7n s\u1ed1\u201d v\u00e0 bi\u1ec3u di\u1ec5n \u1edf bi\u1ec3u \u0111\u1ed3 sau theo s\u1ed1 chim b\u1ed3 c\u00e2u $(x)$ v\u00e0 \u201ct\u1ea7n s\u1ed1\u201d $(n)$ <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop7/toan/daiso/bai22/lv2/img\/D7B22TB1_1.png' \/><\/center> T\u1eeb bi\u1ec3u \u0111\u1ed3 tr\u00ean, h\u00e3y \u0111i\u1ec1n v\u00e0o c\u00e1c \u00f4 tr\u1ed1ng trong b\u1ea3ng \u201ct\u1ea7n s\u1ed1\u201d sau: <br\/> <table><tr><th>Gi\u00e1 tr\u1ecb $(x)$<\/th><th>6<\/th><th>7<\/th><th>11<\/th><th>12<\/th><th><\/th><\/tr><tr><td>T\u1ea7n s\u1ed1 $(n)$<\/td><td>_input_<\/td><td>_input_<\/td><td>_input_<\/td><td>_input_<\/td><td>$N=$ _input_<\/td><\/tr><\/table> <\/span>","explain":"<span class='basic_left'> T\u1eeb bi\u1ec3u \u0111\u1ed3 ta c\u00f3 b\u1ea3ng \u201ct\u1ea7n s\u1ed1\u201d t\u01b0\u01a1ng \u1ee9ng nh\u01b0 sau: <br\/> <table><tr><th>Gi\u00e1 tr\u1ecb $(x)$<\/th><th>6<\/th><th>7<\/th><th>11<\/th><th>12<\/th><th><\/th><\/tr><tr><td>T\u1ea7n s\u1ed1 $(n)$<\/td><td>3<\/td><td>5<\/td><td>10<\/td><td>4<\/td><td>$N=22$<\/td><\/tr><\/table> <br\/> <span class='basic_pink'> V\u1eady c\u00e1c s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o c\u00e1c \u00f4 tr\u1ed1ng l\u1ea7n l\u01b0\u1ee3t l\u00e0 $3;5;10;4;22.$<\/span><\/span>"}]}],"id_ques":961},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["4"],["9"],["8"],["3"],["6"],["30"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":" <span class='basic_left'> Ng\u01b0\u1eddi ta th\u1ed1ng k\u00ea th\u1eddi gian gi\u1ea3i m\u1ed9t b\u00e0i to\u00e1n t\u00ednh theo ph\u00fat c\u1ee7a c\u00e1c h\u1ecdc sinh trong m\u1ed9t l\u1edbp h\u1ecdc r\u1ed3i l\u1eadp b\u1ea3ng \u201ct\u1ea7n s\u1ed1\u201d v\u00e0 bi\u1ec3u di\u1ec5n \u1edf bi\u1ec3u \u0111\u1ed3 tr\u00ean theo th\u1eddi gian gi\u1ea3i m\u1ed9t b\u00e0i to\u00e1n t\u00ednh theo ph\u00fat $(x)$ v\u00e0 \u201ct\u1ea7n s\u1ed1\u201d $(n)$ <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop7/toan/daiso/bai22/lv2/img\/D7B22TB1_2.png' \/><\/center> T\u1eeb bi\u1ec3u \u0111\u1ed3 tr\u00ean, h\u00e3y \u0111i\u1ec1n v\u00e0o c\u00e1c \u00f4 tr\u1ed1ng trong b\u1ea3ng \u201ct\u1ea7n s\u1ed1\u201d sau: <br\/> <table><tr><th>Gi\u00e1 tr\u1ecb $(x)$<\/th><th>3<\/th><th>4<\/th><th>6<\/th><th>8<\/th><th>9<\/th><th><\/th><\/tr><tr><td>T\u1ea7n s\u1ed1 $(n)$<\/td><td>_input_<\/td><td>_input_<\/td><td>_input_<\/td><td>_input_<\/td><td>_input_<\/td><td>$N=$ _input_<\/td><\/tr><\/table> <\/span>","explain":"<span class='basic_left'> T\u1eeb bi\u1ec3u \u0111\u1ed3 ta c\u00f3 b\u1ea3ng \u201ct\u1ea7n s\u1ed1\u201d t\u01b0\u01a1ng \u1ee9ng nh\u01b0 sau: <br\/> <table><tr><th>Gi\u00e1 tr\u1ecb $(x)$<\/th><th>3<\/th><th>4<\/th><th>6<\/th><th>8<\/th><th>9<\/th><th><\/th><\/tr><tr><td>T\u1ea7n s\u1ed1 $(n)$<\/td><td>4<\/td><td>9<\/td><td>8<\/td><td>3<\/td><td>6<\/td><td>$N=30$<\/td><\/tr><\/table> <br\/> <span class='basic_pink'> V\u1eady c\u00e1c s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o c\u00e1c \u00f4 tr\u1ed1ng l\u1ea7n l\u01b0\u1ee3t l\u00e0 $4;9;8;3;6;30$<\/span><\/span>"}]}],"id_ques":962},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":5,"ques":" Cho bi\u1ec3u \u0111\u1ed3 h\u00ecnh ch\u1eef nh\u1eadt v\u1edbi tr\u1ee5c ho\u00e0nh l\u00e0 <b> gi\u00e1 tr\u1ecb $(x)$ <\/b> , tr\u1ee5c tung l\u00e0 <b>t\u1ea7n s\u1ed1 $(n)$<\/b>. <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop7/toan/daiso/bai22/lv2/img\/D7B22TB1_3.png' \/><\/center> S\u1ed1 c\u00e1c gi\u00e1 tr\u1ecb l\u00e0: ","select":["A. $39$","B. $38$","C. $37$","D. $36$"],"explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/>S\u1ed1 c\u00e1c gi\u00e1 tr\u1ecb b\u1eb1ng t\u1ed5ng c\u00e1c t\u1ea7n s\u1ed1 c\u1ee7a c\u00e1c gi\u00e1 tr\u1ecb. <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>Nh\u00ecn v\u00e0o bi\u1ec3u \u0111\u1ed3, ta c\u00f3: <br\/> - C\u00e1c gi\u00e1 tr\u1ecb kh\u00e1c nhau l\u00e0: $4;5;6;7;8;9$ <br\/> - T\u1ea7n s\u1ed1 t\u01b0\u01a1ng \u1ee9ng v\u1edbi c\u00e1c gi\u00e1 tr\u1ecb tr\u00ean l\u00e0: $4; 7; 3;8;5;9$ <br\/> Do \u0111\u00f3, s\u1ed1 c\u00e1c gi\u00e1 tr\u1ecb l\u00e0: <br\/> $N = 4+7+3+8+5+9=36$ <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 D.<\/span><\/span>","column":4}]}],"id_ques":963},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" Cho bi\u1ec3u \u0111\u1ed3 h\u00ecnh ch\u1eef nh\u1eadt v\u1edbi tr\u1ee5c ho\u00e0nh l\u00e0 <b> gi\u00e1 tr\u1ecb $(x)$ <\/b> , tr\u1ee5c tung l\u00e0 <b>t\u1ea7n s\u1ed1 $(n)$<\/b>. <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop7/toan/daiso/bai22/lv2/img\/D7B22TB1_4.png' \/><\/center> M\u1ed1t c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0: ","select":["A. $11$","B. $9$","C. $12$","D. $15$"],"explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/>M\u1ed1t c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0 <b>gi\u00e1 tr\u1ecb c\u00f3 t\u1ea7n s\u1ed1 l\u1edbn nh\u1ea5t<\/b> trong b\u1ea3ng \u201ct\u1ea7n s\u1ed1\u201d; k\u00ed hi\u1ec7u l\u00e0 $M_o$ <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>Nh\u00ecn v\u00e0o bi\u1ec3u \u0111\u1ed3 ta c\u00f3 b\u1ea3ng \u201ct\u1ea7n s\u1ed1\u201d nh\u01b0 sau: <br\/> <table><tr><th>Gi\u00e1 tr\u1ecb $(x)$<\/th><th>6<\/th><th>7<\/th><th>9<\/th><th>10<\/th><th>11<\/th><th>12<\/th><th><\/th><\/tr><tr><td>T\u1ea7n s\u1ed1 $(n)$<\/td><td>4<\/td><td>5<\/td><td>7<\/td><td>6<\/td><td>9<\/td><td>3<\/td><td>$N=34$<\/td><\/tr><\/table> <br\/> Theo b\u1ea3ng \u201ct\u1ea7n s\u1ed1\u201d th\u00ec gi\u00e1 tr\u1ecb $11$ c\u00f3 t\u1ea7n s\u1ed1 l\u1edbn nh\u1ea5t l\u00e0 $9.$ <br\/> Do \u0111\u00f3 m\u1ed1t c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0 $11. $ <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 A.<\/span><\/span>","column":4}]}],"id_ques":964},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["40"],["17"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":" <span class='basic_left'> Cho b\u1ea3ng \u201ct\u1ea7n s\u1ed1\u201d c\u00e1c gi\u00e1 tr\u1ecb c\u1ee7a m\u1ed9t d\u1ea5u hi\u1ec7u. Bi\u1ebft s\u1ed1 trung b\u00ecnh c\u1ed9ng c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0 $36.$ T\u00ednh $x, y.$ <br\/> <table><tr><th>Gi\u00e1 tr\u1ecb $(x)$<\/th><th>30<\/th><th>34<\/th><th>37<\/th><th>x<\/th><th>45<\/th><th><\/th><\/tr><tr><td>T\u1ea7n s\u1ed1 $(n)$<\/td><td>14<\/td><td>9<\/td><td>7<\/td><td>y<\/td><td>3<\/td><td>$N=50$<\/td><\/tr><\/table> <br\/><b> \u0110\u00e1p \u00e1n: <\/b> $x=\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{};y=\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}$ <\/span>","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/>T\u00ecm $y$ th\u00f4ng qua s\u1ed1 c\u00e1c gi\u00e1 tr\u1ecb. <br\/> T\u00ecm $x$ th\u00f4ng qua x\u00e9t c\u00f4ng th\u1ee9c t\u00ednh s\u1ed1 trung b\u00ecnh c\u1ed9ng c\u1ee7a d\u1ea5u hi\u1ec7u. <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>Theo b\u00e0i, s\u1ed1 c\u00e1c gi\u00e1 tr\u1ecb l\u00e0 $50$ n\u00ean ta c\u00f3: <br\/> $\\begin{align} & 14+9+7+y+3=50 \\\\ & \\Rightarrow 33+y=50 \\\\ & \\Rightarrow y=50-33 \\\\ & \\Rightarrow y=17 \\\\ \\end{align}$ <br\/> Ta c\u00f3: <br\/>$\\begin{align} & \\overline{X}=\\dfrac{30.14+34.9+37.7+x.17+45.3}{50}=36 \\\\ & \\Leftrightarrow \\dfrac{1120+x.17}{50}=36 \\\\ & \\Leftrightarrow 1120+17x=1800 \\\\ & \\Leftrightarrow 17x=1800-1120 \\\\ & \\Leftrightarrow 17x=680 \\\\ & \\Leftrightarrow x=680:17=40 \\\\ \\end{align}$ <br\/> <span class='basic_pink'> V\u1eady c\u00e1c s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o c\u00e1c \u00f4 tr\u1ed1ng l\u1ea7n l\u01b0\u1ee3t l\u00e0 $40;17.$<\/span><\/span>"}]}],"id_ques":965},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"\u0110\u1ec1 chung cho hai c\u00e2u","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":" <span class='basic_left'>Chi\u1ec1u cao c\u1ee7a m\u1ed7i c\u1ea7u th\u1ee7 trong m\u1ed9t \u0111\u1ed9i b\u00f3ng \u0111\u01b0\u1ee3c cho trong b\u1ea3ng sau (\u0111\u01a1n v\u1ecb cm): <br\/> <table><tr><th>170<\/th><th>178<\/th><th>180<\/th><th>175<\/th><th>174<\/th><th>180<\/th><th>178<\/th><th>180<\/th><th>178<\/th><\/tr><tr><td>174<\/td><td>178<\/td><td>184<\/td><td>170<\/td><td>175<\/td><td>180<\/td><td>178<\/td><td>175<\/td><td>174<\/td><\/tr><\/table> <br\/> <b> C\u00e2u 1.<\/b> M\u1ed1t c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0: <\/span>","select":["A. $180$","B. $5$","C. $178$","D. $18$"],"explain":"<span class='basic_left'>Ta c\u00f3 b\u1ea3ng \u201ct\u1ea7n s\u1ed1\u201d theo b\u1ea3ng s\u1ed1 li\u1ec7u ban \u0111\u1ea7u nh\u01b0 sau: <br\/> <table><tr><th>Chi\u1ec1u cao $(x)$<\/th><th>170<\/th><th>174<\/th><th>175<\/th><th>178<\/th><th>180<\/th><th>184<\/th><th><\/th><\/tr><tr><td>T\u1ea7n s\u1ed1 $(n)$<\/td><td>2<\/td><td>3<\/td><td>3<\/td><td>5<\/td><td>4<\/td><td>1<\/td><td>$N=18$<\/td><\/tr><\/table> <br\/> Ta th\u1ea5y gi\u00e1 tr\u1ecb $178$ c\u00f3 t\u1ea7n s\u1ed1 l\u1edbn nh\u1ea5t l\u00e0 $5.$ <br\/> Do \u0111\u00f3 m\u1ed1t c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0 $178.$ <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 C.<\/span><\/span>","column":4}]}],"id_ques":966},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"\u0110\u1ec1 chung cho hai c\u00e2u","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" <span class='basic_left'>Chi\u1ec1u cao c\u1ee7a m\u1ed7i c\u1ea7u th\u1ee7 trong m\u1ed9t \u0111\u1ed9i b\u00f3ng \u0111\u01b0\u1ee3c cho trong b\u1ea3ng sau (\u0111\u01a1n v\u1ecb cm): <br\/> <table><tr><th>170<\/th><th>178<\/th><th>180<\/th><th>175<\/th><th>174<\/th><th>180<\/th><th>178<\/th><th>180<\/th><th>178<\/th><\/tr><tr><td>174<\/td><td>178<\/td><td>184<\/td><td>170<\/td><td>175<\/td><td>180<\/td><td>178<\/td><td>175<\/td><td>174<\/td><\/tr><\/table> <br\/> <b> C\u00e2u 2.<\/b> Chi\u1ec1u cao trung b\u00ecnh c\u1ee7a m\u1ed7i c\u1ea7u th\u1ee7 l\u00e0: <\/span>","select":["A. $176,72\\,cm$","B. $175 \\,cm$","C. $177\\,cm$","D. $175,83\\,cm$"],"explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/>T\u00ednh s\u1ed1 trung b\u00ecnh c\u1ed9ng c\u1ee7a d\u1ea5u hi\u1ec7u theo c\u00f4ng th\u1ee9c. <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3 b\u1ea3ng \u201ct\u1ea7n s\u1ed1\u201d (theo c\u00e2u 1) nh\u01b0 sau: <br\/> <table><tr><th>Chi\u1ec1u cao $(x)$<\/th><th>170<\/th><th>174<\/th><th>175<\/th><th>178<\/th><th>180<\/th><th>184<\/th><th><\/th><\/tr><tr><td>T\u1ea7n s\u1ed1 $(n)$<\/td><td>2<\/td><td>3<\/td><td>3<\/td><td>5<\/td><td>4<\/td><td>1<\/td><td>$N=18$<\/td><\/tr><\/table> <br\/> Chi\u1ec1u cao trung b\u00ecnh c\u1ee7a m\u1ed7i c\u1ea7u th\u1ee7 l\u00e0: <br\/> $\\begin{align} & \\overline{X}=\\dfrac{170.2+174.3+175.3+178.5+180.4+184.1}{18} \\\\ & \\,\\,\\,\\,\\,\\,=\\dfrac{3181}{18} \\\\ & \\,\\,\\,\\,\\,\\,=176,72 \\,(cm) \\\\ \\end{align}$ <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 A.<\/span><\/span>","column":4}]}],"id_ques":967},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" <span class='basic_left'>Cho bi\u1ec3u \u0111\u1ed3 sau, th\u1ec3 hi\u1ec7n s\u1ed1 h\u1ecdc sinh gi\u1ecfi b\u1ed9 m\u00f4n trong m\u1ed9t l\u1edbp h\u1ecdc (\u0111\u01a1n v\u1ecb c\u00e1c c\u1ed9t l\u00e0: h\u1ecdc sinh): <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop7/toan/daiso/bai22/lv2/img\/D7B22TB1_7.png' \/><\/center> Kh\u1eb3ng \u0111\u1ecbnh n\u00e0o \u0111\u00fang trong c\u00e1c kh\u1eb3ng \u0111\u1ecbnh sau? <\/span>","select":["A. M\u00f4n To\u00e1n c\u00f3 nhi\u1ec1u h\u1ecdc sinh gi\u1ecfi nh\u1ea5t, m\u00f4n S\u1eed c\u00f3 \u00edt h\u1ecdc sinh gi\u1ecfi nh\u1ea5t.","B. M\u00f4n V\u0103n c\u00f3 \u00edt h\u1ecdc sinh gi\u1ecfi nh\u1ea5t l\u00e0 $12$ h\u1ecdc sinh","C. M\u00f4n Ngo\u1ea1i ng\u1eef c\u00f3 nhi\u1ec1u h\u1ecdc sinh gi\u1ecfi nh\u1ea5t l\u00e0 $20$ h\u1ecdc sinh"],"explain":"<span class='basic_left'>M\u00f4n To\u00e1n c\u00f3 nhi\u1ec1u h\u1ecdc sinh gi\u1ecfi nh\u1ea5t, m\u00f4n S\u1eed c\u00f3 \u00edt h\u1ecdc sinh gi\u1ecfi nh\u1ea5t. <br\/> Do \u0111\u00f3 kh\u1eb3ng \u0111\u1ecbnh \u0111\u00fang l\u00e0 A. <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 A.<\/span><\/span>","column":1}]}],"id_ques":968},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["15"],["5"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":" <span class='basic_left'> M\u1ed9t v\u1eadn \u0111\u1ed9ng vi\u00ean n\u00e9m b\u00f3ng r\u1ed5, s\u1ed1 l\u1ea7n b\u00f3ng v\u00e0o r\u1ed5 c\u1ee7a m\u1ed7i ph\u00fat t\u1eadp luy\u1ec7n \u0111\u01b0\u1ee3c ghi l\u1ea1i nh\u01b0 sau: <br\/> <table><tr><th>Gi\u00e1 tr\u1ecb $(x)$<\/th><th>5<\/th><th>6<\/th><th>7<\/th><th>8<\/th><th>9<\/th><th>10<\/th><th>11<\/th><th>12<\/th><th>13<\/th><th>14<\/th><th>a<\/th><th><\/th><\/tr><tr><td>T\u1ea7n s\u1ed1 $(n)$<\/td><td>5<\/td><td>3<\/td><td>5<\/td><td>5<\/td><td>9<\/td><td>2<\/td><td>1<\/td><td>5<\/td><td>5<\/td><td>5<\/td><td>b<\/td><td>$N=50$<\/td><\/tr><\/table> <br\/> T\u00ecm $a, b$ bi\u1ebft s\u1ed1 trung b\u00ecnh c\u1ed9ng l\u00e0 $10.$ <br\/><b> \u0110\u00e1p \u00e1n: <\/b> $a=\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{};b=\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}$ <\/span>","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/>Do $N$ b\u1eb1ng t\u1ed5ng t\u1ea7n s\u1ed1 c\u1ee7a c\u00e1c gi\u00e1 tr\u1ecb n\u00ean ta t\u00ecm \u0111\u01b0\u1ee3c $b.$ <br\/> T\u1eeb c\u00f4ng th\u1ee9c t\u00ednh s\u1ed1 trung b\u00ecnh c\u1ed9ng c\u1ee7a d\u1ea5u hi\u1ec7u t\u00ecm \u0111\u01b0\u1ee3c $a.$ <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3: <br\/> $\\begin{align} & 5+3+5+5+9+2+1+5+5+5+b=50 \\\\ & \\Leftrightarrow 45+b=50 \\\\ & \\Leftrightarrow b=50-45 \\\\ & \\Leftrightarrow b=5 \\\\ \\end{align}$ <br\/> Ta c\u00f3: <br\/> $\\begin{align} & \\overline{X}=\\dfrac{5.5+6.3+7.5+8.5+9.9+10.2+11.1+12.5+13.5+14.5+a.5}{50} \\\\ & \\,\\,\\,\\,\\,\\,=\\frac{425+5a}{50} \\\\ \\end{align}$<br\/> M\u00e0 s\u1ed1 trung b\u00ecnh c\u1ed9ng c\u1ee7a d\u1ea5u hi\u1ec7u b\u1eb1ng $10$ n\u00ean: <br\/> $\\begin{align} & \\overline{X}=10 \\\\ & \\Rightarrow \\dfrac{425+5a}{50}=10 \\\\ & \\Rightarrow 425+5a=500 \\\\ & \\Rightarrow 5a=500-425 \\\\ & \\Rightarrow 5a=75 \\\\ & \\Rightarrow a=15 \\\\ \\end{align}$ <br\/> Do \u0111\u00f3 $a =15; b=5$ <br\/> <span class='basic_pink'> V\u1eady c\u00e1c s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o c\u00e1c \u00f4 tr\u1ed1ng l\u1ea7n l\u01b0\u1ee3t l\u00e0 $15;5.$<\/span><\/span>"}]}],"id_ques":969},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":" <span class='basic_left'>T\u00ednh s\u1ed1 trung b\u00ecnh c\u1ed9ng c\u1ee7a n\u0103m g\u00f3i h\u00e0ng trong \u0111\u00f3 c\u00f3 hai g\u00f3i kh\u1ed1i l\u01b0\u1ee3ng $2,3$ kg, m\u1ed9t g\u00f3i kh\u1ed1i l\u01b0\u1ee3ng $2,4$ kg v\u00e0 hai g\u00f3i kh\u1ed1i l\u01b0\u1ee3ng $2,5$ kg.<\/span>","select":["A. $2$ kg","B. $2,3$ kg","C. $2,4$ kg","D. $2,5$ kg"],"explain":"<span class='basic_left'>S\u1ed1 trung b\u00ecnh c\u1ed9ng c\u1ee7a n\u0103m g\u00f3i h\u00e0ng l\u00e0: <br\/> $\\dfrac{2.2,3+1.2,4+2.2,5}{5}=\\dfrac{12}{5}=2,4$ (kg) <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 C.<\/span><\/span>","column":4}]}],"id_ques":970},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" <span class='basic_left'>Kh\u1eb3ng \u0111\u1ecbnh sau \u0111\u00e2y \u0111\u00fang hay sai? <br\/> Khi c\u00e1c gi\u00e1 tr\u1ecb c\u1ee7a d\u1ea5u hi\u1ec7u c\u00f3 kho\u1ea3ng ch\u00eanh l\u1ec7ch r\u1ea5t l\u1edbn \u0111\u1ed1i v\u1edbi nhau th\u00ec kh\u00f4ng n\u00ean l\u1ea5y s\u1ed1 trung b\u00ecnh c\u1ed9ng l\u00e0m \u201c\u0111\u1ea1i di\u1ec7n\u201d cho d\u1ea5u hi\u1ec7u \u0111\u00f3.<\/span>","select":["\u0110\u00fang","Sai"],"explain":"<span class='basic_left'>Kh\u1eb3ng \u0111\u1ecbnh tr\u00ean l\u00e0 \u0110\u00fang. <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 \u0110\u00fang.<\/span><\/span>","column":2}]}],"id_ques":971},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["40"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":" <span class='basic_left'> B\u1ed1n b\u1ea1n h\u1ecdc sinh c\u00f3 c\u00e2n n\u1eb7ng trung b\u00ecnh l\u00e0 $35$ kg. Khi c\u00f3 th\u00eam m\u1ed9t b\u1ea1n m\u1edbi th\u00ec c\u00e2n n\u1eb7ng trung b\u00ecnh c\u1ee7a n\u0103m b\u1ea1n l\u00e0 $36$ kg. B\u1ea1n m\u1edbi c\u00f3 c\u00e2n n\u1eb7ng l\u00e0 _input_ (kg) <\/span>","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/>C\u00e2n n\u1eb7ng c\u1ee7a b\u1ea1n h\u1ecdc sinh m\u1edbi = (t\u1ed5ng c\u00e2n n\u1eb7ng c\u1ee7a $5$ b\u1ea1n h\u1ecdc sinh l\u00fac sau) \u2013 (t\u1ed5ng c\u00e2n n\u1eb7ng c\u1ee7a $4$ b\u1ea1n h\u1ecdc sinh ban \u0111\u1ea7u) <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>T\u1ed5ng c\u00e2n n\u1eb7ng c\u1ee7a $4$ b\u1ea1n h\u1ecdc sinh (khi ch\u01b0a c\u00f3 b\u1ea1n m\u1edbi) l\u00e0: <br\/> $35.4=140$ (kg) <br\/> T\u1ed5ng c\u00e2n n\u1eb7ng c\u1ee7a $5$ b\u1ea1n h\u1ecdc sinh (khi c\u00f3 b\u1ea1n m\u1edbi) l\u00e0: <br\/> $36.5=180$ (kg) <br\/> C\u00e2n n\u1eb7ng c\u1ee7a b\u1ea1n h\u1ecdc sinh m\u1edbi l\u00e0: <br\/> $180-140=40$ (kg) <br\/> <span class='basic_pink'> V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $40$<\/span><\/span>"}]}],"id_ques":972},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" <span class='basic_left'>Chi\u1ec1u cao t\u00ednh b\u1eb1ng mm c\u1ee7a 100 c\u00e2y ch\u00e8 sau m\u1ed9t th\u1eddi gian tr\u1ed3ng th\u1ef1c nghi\u1ec7m \u0111\u01b0\u1ee3c cho theo b\u1ea3ng sau: <br\/> <table><tr><th>Chi\u1ec1u cao (x\u1ebfp theo kho\u1ea3ng)<\/th><th>T\u1ea7n s\u1ed1<\/th><\/tr><tr><td>150-152<\/td><td>5<\/td><\/tr><tr><td>153-155<\/td><td>6<\/td><\/tr><tr><td>156-158<\/td><td>25<\/td><\/tr><tr><td>159-161<\/td><td>35<\/td><\/tr><tr><td>162-164<\/td><td>8<\/td><\/tr><tr><td>165-167<\/td><td>15<\/td><\/tr><tr><td>168-170<\/td><td>6<\/td><\/tr><\/table> <br\/> S\u1ed1 trung b\u00ecnh c\u1ed9ng chi\u1ec1u cao c\u1ee7a m\u1ed7i c\u00e2y ch\u00e8 l\u00e0:<\/span>","select":["A. $160,12\\, mm$","B. $159\\,mm$","C. $162\\,mm$","D. $163,24\\,mm$"],"explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/>T\u00ednh s\u1ed1 trung b\u00ecnh c\u1ed9ng c\u1ee7a t\u1eebng kho\u1ea3ng. S\u1ed1 \u0111\u00f3 ch\u00ednh l\u00e0 trung b\u00ecnh c\u1ed9ng c\u1ee7a gi\u00e1 tr\u1ecb l\u1edbn nh\u1ea5t v\u00e0 nh\u1ecf nh\u1ea5t c\u1ee7a kho\u1ea3ng. V\u00ed d\u1ee5 trung b\u00ecnh c\u1ed9ng c\u1ee7a kho\u1ea3ng $150-152$ l\u00e0 $151.$ <br\/> Nh\u00e2n c\u00e1c s\u1ed1 trung b\u00ecnh v\u1eeba t\u00ecm \u0111\u01b0\u1ee3c v\u1edbi c\u00e1c t\u1ea7n s\u1ed1 t\u01b0\u01a1ng \u1ee9ng. <br\/> T\u00ecm s\u1ed1 trung b\u00ecnh c\u1ed9ng theo c\u00f4ng th\u1ee9c \u0111\u00e3 h\u1ecdc. <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3 b\u1ea3ng sau: <br\/> <table><tr><th>Chi\u1ec1u cao (x\u1ebfp theo kho\u1ea3ng)<\/th><th>Gi\u00e1 tr\u1ecb trung b\u00ecnh<\/th><th>T\u1ea7n s\u1ed1<\/th><th>C\u00e1c t\u00edch<\/th><th><\/th><\/tr><tr><td>150-152<\/td><td>151<\/td><td>5<\/td><td>755<\/td><td><\/td><\/tr><tr><td>153-155<\/td><td>154<\/td><td>6<\/td><td>924<\/td><td><\/td><\/tr><tr><td>156-158<\/td><td>157<\/td><td>25<\/td><td>3925<\/td><td><\/td><\/tr><tr><td>159-161<\/td><td>160<\/td><td>35<\/td><td>5600<\/td><td><\/td><\/tr><tr><td>162-164<\/td><td>163<\/td><td>8<\/td><td>1304<\/td><td><\/td><\/tr><tr><td>165-167<\/td><td>166<\/td><td>15<\/td><td>2490<\/td><td><\/td><\/tr><tr><td>168-170<\/td><td>169<\/td><td>6<\/td><td>1014<\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><td>$N=100$<\/td><td>T\u1ed5ng: 16012<\/td><td>$\\overline{X}=\\dfrac{16012}{100}=160,12$ <\/td><\/tr><\/table> <br\/> V\u1eady chi\u1ec1u cao trung b\u00ecnh c\u1ee7a m\u1ed7i c\u00e2y ch\u00e8 l\u00e0 $160,12 \\,(mm)$ <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 A.<\/span><\/span>","column":4}]}],"id_ques":973},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["12"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":" <span class='basic_left'> Cho bi\u1ec3u \u0111\u1ed3 h\u00ecnh ch\u1eef nh\u1eadt sau: <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop7/toan/daiso/bai22/lv2/img\/D7B22TB1_13.png' \/><\/center> Nh\u00ecn v\u00e0o bi\u1ec3u \u0111\u1ed3 \u0111\u00e3 cho v\u00e0 t\u00ecm m\u1ed1t c\u1ee7a d\u1ea5u hi\u1ec7u. <br\/> <b>\u0110\u00e1p \u00e1n:<\/b> M\u1ed1t c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0 _input_ <\/span>","explain":"<span class='basic_left'>Nh\u00ecn v\u00e0o bi\u1ec3u \u0111\u1ed3 \u0111\u00e3 cho, ta th\u1ea5y gi\u00e1 tr\u1ecb $12$ c\u00f3 t\u1ea7n s\u1ed1 l\u1edbn nh\u1ea5t l\u00e0 $8.$ <br\/> Do \u0111\u00f3, m\u1ed1t c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0 $12.$ <br\/> <span class='basic_pink'> V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $12$<\/span><\/span>"}]}],"id_ques":974},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" <span class='basic_left'>Cho bi\u1ec3u \u0111\u1ed3 h\u00ecnh ch\u1eef nh\u1eadt sau: <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop7/toan/daiso/bai22/lv2/img\/D7B22TB1_14.png' \/><\/center> Nh\u00ecn v\u00e0o bi\u1ec3u \u0111\u1ed3 \u0111\u00e3 cho, m\u1ed9t b\u1ea1n h\u1ecdc sinh c\u00f3 nh\u1eadn x\u00e9t nh\u01b0 sau: <br\/> - Gi\u00e1 tr\u1ecb l\u1edbn nh\u1ea5t l\u00e0 $11$ <br\/> - Gi\u00e1 tr\u1ecb nh\u1ecf nh\u1ea5t l\u00e0 $6$ <br\/> - Gi\u00e1 tr\u1ecb c\u00f3 t\u1ea7n s\u1ed1 l\u1edbn nh\u1ea5t l\u00e0 $10$ <br\/> - Gi\u00e1 tr\u1ecb c\u00f3 t\u1ea7n s\u1ed1 nh\u1ecf nh\u1ea5t l\u00e0 $7$ <br\/> Nh\u1eefng nh\u1eadn x\u00e9t tr\u00ean c\u1ee7a b\u1ea1n h\u1ecdc sinh \u0110\u00fang hay Sai? <\/span>","select":["\u0110\u00fang","Sai"],"explain":"<span class='basic_left'>D\u1ef1a v\u00e0o bi\u1ec3u \u0111\u1ed3 \u0111\u00e3 cho ta c\u00f3 b\u1ea3ng ''t\u1ea7n s\u1ed1'' t\u01b0\u01a1ng \u1ee9ng nh\u01b0 sau: <br\/> <table><tr><th>Gi\u00e1 tr\u1ecb $(x)$<\/th><th>6<\/th><th>7<\/th><th>9<\/th><th>10<\/th><th>11<\/th><th><\/th><\/tr><tr><td>T\u1ea7n s\u1ed1 $(n)$<\/td><td>8<\/td><td>2<\/td><td>3<\/td><td>9<\/td><td>5<\/td><td>$N=27$<\/td><\/tr><\/table> T\u1eeb b\u1ea3ng ''t\u1ea7n s\u1ed1'' ta nh\u1eadn th\u1ea5y: <br\/> - Gi\u00e1 tr\u1ecb l\u1edbn nh\u1ea5t l\u00e0 $11$ <br\/> - Gi\u00e1 tr\u1ecb nh\u1ecf nh\u1ea5t l\u00e0 $6$ <br\/> - Gi\u00e1 tr\u1ecb c\u00f3 t\u1ea7n s\u1ed1 l\u1edbn nh\u1ea5t l\u00e0 $10$ <br\/> - Gi\u00e1 tr\u1ecb c\u00f3 t\u1ea7n s\u1ed1 nh\u1ecf nh\u1ea5t l\u00e0 $7$ <br\/> Do \u0111\u00f3 nh\u1eefng nh\u1eadn x\u00e9t c\u1ee7a b\u1ea1n h\u1ecdc sinh l\u00e0 \u0111\u00fang. <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 \u0110\u00fang.<\/span><\/span>","column":2}]}],"id_ques":975},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["10"],["5"],["8,51","8.51"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":" <span class='basic_left'> Cho bi\u1ec3u \u0111\u1ed3 h\u00ecnh ch\u1eef nh\u1eadt sau: <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop7/toan/daiso/bai22/lv2/img\/D7B22TB1_15.png' \/><\/center> D\u1ef1a v\u00e0o bi\u1ec3u \u0111\u1ed3 \u0111\u00e3 cho, \u0111i\u1ec1n v\u00e0o c\u00e1c \u00f4 tr\u1ed1ng trong c\u00e1c c\u00e2u sau: <br\/> - T\u1ea7n s\u1ed1 l\u1edbn nh\u1ea5t l\u00e0 _input_ <br\/> - M\u1ed1t c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0 _input_<br\/> - S\u1ed1 trung b\u00ecnh c\u1ed9ng c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0 (l\u00e0m tr\u00f2n \u0111\u1ebfn ch\u1eef s\u1ed1 th\u1eadp ph\u00e2n th\u1ee9 hai) _input_ <\/span>","explain":"<span class='basic_left'>D\u1ef1a v\u00e0o bi\u1ec3u \u0111\u1ed3 \u0111\u00e3 cho ta c\u00f3 b\u1ea3ng ''t\u1ea7n s\u1ed1'' k\u00e8m theo c\u1ed9t t\u00ednh s\u1ed1 trung b\u00ecnh c\u1ed9ng t\u01b0\u01a1ng \u1ee9ng nh\u01b0 sau: <br\/> <table><tr><th>Gi\u00e1 tr\u1ecb $(x)$<\/th><th>T\u1ea7n s\u1ed1 $(n)$<\/th><th>T\u00edch $(x.n)$<\/th><th><\/th><\/tr><tr><td>5<\/td><td>10<\/td><td>50<\/td><td><\/td><\/tr><tr><td>7<\/td><td>9<\/td><td>63<\/td><td><\/td><\/tr><tr><td>9<\/td><td>4<\/td><td>36<\/td><td><\/td><\/tr><tr><td>10<\/td><td>5<\/td><td>50<\/td><td><\/td><\/tr><tr><td>11<\/td><td>6<\/td><td>66<\/td><td><\/td><\/tr><tr><td>12<\/td><td>7<\/td><td>84<\/td><td><\/td><\/tr><tr><td><\/td><td>$N=41$<\/td><td>T\u1ed5ng: 349<\/td><td>$\\overline{X}=\\dfrac{349}{41}=8,51$ <\/td><\/tr><\/table> <br\/> T\u1eeb b\u1ea3ng ''t\u1ea7n s\u1ed1'' tr\u00ean, ta c\u00f3: <br\/> - T\u1ea7n s\u1ed1 l\u1edbn nh\u1ea5t l\u00e0 $10$ <br\/> - Gi\u00e1 tr\u1ecb $5$ c\u00f3 t\u1ea7n s\u1ed1 l\u1edbn nh\u1ea5t l\u00e0 $10$ n\u00ean m\u1ed1t c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0 $5.$ <br\/> - S\u1ed1 trung b\u00ecnh c\u1ed9ng c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0 $8,51$ <br\/> <span class='basic_pink'> V\u1eady c\u00e1c s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o c\u00e1c \u00f4 tr\u1ed1ng l\u00e0 $10; 5$ v\u00e0 $ 8,51$<\/span><\/span>"}]}],"id_ques":976},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["11"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":" <span class='basic_left'> Trung b\u00ecnh c\u1ed9ng c\u1ee7a s\u00e1u s\u1ed1 l\u00e0 $4.$ Do th\u00eam s\u1ed1 th\u1ee9 $7$ n\u00ean trung b\u00ecnh c\u1ed9ng c\u1ee7a b\u1ea3y s\u1ed1 l\u00e0 $5.$ T\u00ecm s\u1ed1 th\u1ee9 b\u1ea3y. <br\/> <b>\u0110\u00e1p \u00e1n: <\/b> S\u1ed1 th\u1ee9 b\u1ea3y l\u00e0 _input_ <\/span>","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/>S\u1ed1 th\u1ee9 b\u1ea3y = (T\u1ed5ng c\u1ee7a b\u1ea3y s\u1ed1 l\u00fac sau) \u2013 (T\u1ed5ng c\u1ee7a s\u00e1u s\u1ed1 ban \u0111\u1ea7u) <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> T\u1ed5ng s\u00e1u s\u1ed1 ban \u0111\u1ea7u l\u00e0: $4.6=24$ <br\/> T\u1ed5ng b\u1ea3y s\u1ed1 l\u00fac sau l\u00e0: $5.7=35$ <br\/> S\u1ed1 th\u1ee9 b\u1ea3y l\u00e0: $35-24=11$ <br\/> <span class='basic_pink'> V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $11.$<\/span><\/span>"}]}],"id_ques":977},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"\u0110\u1ec1 chung cho hai c\u00e2u","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" <span class='basic_left'>Sau m\u1ed9t cu\u1ed9c \u0111i\u1ec1u tra tr\u00ecnh \u0111\u1ed9 v\u0103n h\u00f3a t\u1ea1i m\u1ed9t nh\u00e0 xu\u1ea5t b\u1ea3n thu \u0111\u01b0\u1ee3c k\u1ebft qu\u1ea3 nh\u01b0 sau: <br\/> - C\u00f3 $5\\%$ c\u00e1n b\u1ed9 c\u00f4ng nh\u00e2n vi\u00ean h\u1ecdc h\u1ebft c\u1ea5p THCS <br\/> - C\u00f3 $9\\%$ c\u00e1n b\u1ed9 c\u00f4ng nh\u00e2n vi\u00ean h\u1ecdc h\u1ebft c\u1ea5p THPT <br\/> - C\u00f3 $50\\%$ c\u00e1n b\u1ed9 c\u00f4ng nh\u00e2n vi\u00ean h\u1ecdc h\u1ebft \u0111\u1ea1i h\u1ecdc (c\u1eed nh\u00e2n) <br\/> - C\u00f3 $20\\%$ c\u00e1n b\u1ed9 c\u00f4ng nh\u00e2n vi\u00ean h\u1ecdc sau \u0111\u1ea1i h\u1ecdc (th\u1ea1c s\u0129, ti\u1ebfn s\u0129) <br\/> - C\u00f2n l\u1ea1i l\u00e0 c\u00e1n b\u1ed9 c\u00f4ng nh\u00e2n vi\u00ean tr\u00ecnh \u0111\u1ed9 d\u01b0\u1edbi c\u1ea5p THCS. <br\/> Bi\u1ebft r\u1eb1ng t\u1ed5ng s\u1ed1 c\u00e1n b\u1ed9 v\u00e0 c\u00f4ng nh\u00e2n vi\u00ean c\u1ee7a nh\u00e0 xu\u1ea5t b\u1ea3n l\u00e0 $1000$ ng\u01b0\u1eddi. <br\/> <b> C\u00e2u 1. <\/b> Bi\u1ec3u \u0111\u1ed3 th\u1ec3 hi\u1ec7n s\u1ed1 c\u00e1n b\u1ed9 c\u00f4ng nh\u00e2n vi\u00ean tr\u00ecnh t\u1eeb h\u1ebft c\u1ea5p THCS t\u1edbi sau \u0111\u1ea1i h\u1ecdc l\u00e0: <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop7/toan/daiso/bai22/lv2/img\/D7B22TB1_17.png' \/><\/center> <\/span>","select":["\u0110\u00fang","Sai"],"hint":"T\u00ecm s\u1ed1 c\u00e1n b\u1ed9 c\u00f4ng nh\u00e2n vi\u00ean \u1edf t\u1eebng tr\u00ecnh \u0111\u1ed9 t\u1eeb h\u1ebft c\u1ea5p THCS t\u1edbi sau \u0111\u1ea1i h\u1ecdc.","explain":"<span class='basic_left'>S\u1ed1 c\u00e1n b\u1ed9 c\u00f4ng nh\u00e2n vi\u00ean h\u1ecdc h\u1ebft c\u1ea5p THCS l\u00e0: <br\/> $5\\%.1000=\\dfrac{5}{100}\\cdot 1000=50$ (ng\u01b0\u1eddi) <br\/> S\u1ed1 c\u00e1n b\u1ed9 c\u00f4ng nh\u00e2n vi\u00ean h\u1ecdc h\u1ebft c\u1ea5p THPT l\u00e0: <br\/> $9\\%.1000=\\dfrac{9}{100}\\cdot 1000=90$(ng\u01b0\u1eddi) <br\/> S\u1ed1 c\u00e1n b\u1ed9 c\u00f4ng nh\u00e2n vi\u00ean h\u1ecdc h\u1ebft \u0111\u1ea1i h\u1ecdc l\u00e0: <br\/> $50\\%.1000=\\dfrac{50}{100}\\cdot 1000=500$(ng\u01b0\u1eddi) <br\/> S\u1ed1 c\u00e1n b\u1ed9 c\u00f4ng nh\u00e2n vi\u00ean h\u1ecdc sau \u0111\u1ea1i h\u1ecdc l\u00e0: <br\/> $20\\%.1000=\\dfrac{20}{100}\\cdot 1000=200$ (ng\u01b0\u1eddi) <br\/> V\u1eady bi\u1ec3u \u0111\u1ed3 tr\u00ean th\u1ec3 hi\u1ec7n \u0111\u00fang v\u1edbi s\u1ed1 li\u1ec7u \u0111\u1ec1 b\u00e0i. <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 \u0110\u00fang.<\/span><\/span>","column":2}]}],"id_ques":978},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"\u0110\u1ec1 chung cho hai c\u00e2u","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":"<span class='basic_left'>Sau m\u1ed9t cu\u1ed9c \u0111i\u1ec1u tra tr\u00ecnh \u0111\u1ed9 v\u0103n h\u00f3a t\u1ea1i m\u1ed9t nh\u00e0 xu\u1ea5t b\u1ea3n thu \u0111\u01b0\u1ee3c k\u1ebft qu\u1ea3 nh\u01b0 sau: <br\/> - C\u00f3 $5\\%$ c\u00e1n b\u1ed9 c\u00f4ng nh\u00e2n vi\u00ean h\u1ecdc h\u1ebft c\u1ea5p THCS <br\/> - C\u00f3 $9\\%$ c\u00e1n b\u1ed9 c\u00f4ng nh\u00e2n vi\u00ean h\u1ecdc h\u1ebft c\u1ea5p THPT <br\/> - C\u00f3 $50\\%$ c\u00e1n b\u1ed9 c\u00f4ng nh\u00e2n vi\u00ean h\u1ecdc h\u1ebft \u0111\u1ea1i h\u1ecdc (c\u1eed nh\u00e2n) <br\/> - C\u00f3 $20\\%$ c\u00e1n b\u1ed9 c\u00f4ng nh\u00e2n vi\u00ean h\u1ecdc sau \u0111\u1ea1i h\u1ecdc (th\u1ea1c s\u0129, ti\u1ebfn s\u0129) <br\/> - C\u00f2n l\u1ea1i l\u00e0 c\u00e1n b\u1ed9 c\u00f4ng nh\u00e2n vi\u00ean tr\u00ecnh \u0111\u1ed9 d\u01b0\u1edbi c\u1ea5p THCS. <br\/> Bi\u1ebft r\u1eb1ng t\u1ed5ng s\u1ed1 c\u00e1n b\u1ed9 v\u00e0 c\u00f4ng nh\u00e2n vi\u00ean c\u1ee7a nh\u00e0 xu\u1ea5t b\u1ea3n l\u00e0 $1000$ ng\u01b0\u1eddi. <br\/> <b> C\u00e2u 2. <\/b> M\u1ed1t c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0: <\/span>","select":["A. THCS ","B. THPT ","C. \u0110\u1ea1i h\u1ecdc","D. Sau \u0111\u1ea1i h\u1ecdc"],"explain":"<span class='basic_left'>Theo c\u00e2u 1 ta c\u00f3: <br\/> + S\u1ed1 c\u00e1n b\u1ed9 c\u00f4ng nh\u00e2n vi\u00ean h\u1ecdc h\u1ebft c\u1ea5p THCS l\u00e0: $50$ <br\/> + S\u1ed1 c\u00e1n b\u1ed9 c\u00f4ng nh\u00e2n vi\u00ean h\u1ecdc h\u1ebft c\u1ea5p THPT l\u00e0: $90$ <br\/> + S\u1ed1 c\u00e1n b\u1ed9 c\u00f4ng nh\u00e2n vi\u00ean h\u1ecdc h\u1ebft \u0111\u1ea1i h\u1ecdc l\u00e0: $500$ <br\/> + S\u1ed1 c\u00e1n b\u1ed9 c\u00f4ng nh\u00e2n vi\u00ean h\u1ecdc sau \u0111\u1ea1i h\u1ecdc l\u00e0: $200$ <br\/> + S\u1ed1 c\u00e1n b\u1ed9 c\u00f4ng nh\u00e2n vi\u00ean tr\u00ecnh \u0111\u1ed9 d\u01b0\u1edbi c\u1ea5p THCS l\u00e0: $1000-50-90-500-200=160$ <br\/> Trong \u0111\u00f3, s\u1ed1 c\u00f4ng nh\u00e2n vi\u00ean \u1edf tr\u00ecnh \u0111\u1ed9 \u0110\u1ea1i h\u1ecdc c\u00f3 s\u1ed1 ng\u01b0\u1eddi cao nh\u1ea5t l\u00e0 $500$ (ng\u01b0\u1eddi) <br\/> Do \u0111\u00f3, m\u1ed1t c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0 ''\u0110\u1ea1i h\u1ecdc'' <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 C.<\/span><\/span>","column":4}]}],"id_ques":979},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":5,"ques":"<span class='basic_left'>Theo d\u00f5i v\u1eadn t\u1ed1c c\u1ee7a m\u1ed9t \u0111o\u00e0n t\u00e0u h\u1ecfa trong $10$ gi\u1edd, k\u1ebft qu\u1ea3 nh\u01b0 sau: <br\/> <table><tr><th>S\u1ed1 th\u1ee9 t\u1ef1 gi\u1edd ch\u1ea1y<\/th><th>1<\/th><th>2<\/th><th>3<\/th><th>4<\/th><th>5<\/th><th>6<\/th><th>7<\/th><th>8<\/th><th>9<\/th><th>10<\/th><\/tr><tr><td>Qu\u00e3ng \u0111\u01b0\u1eddng \u0111i \u0111\u01b0\u1ee3c (km)<\/td><td>55<\/td><td>58<\/td><td>56<\/td><td>60<\/td><td>57<\/td><td>59<\/td><td>60<\/td><td>55<\/td><td>57<\/td><td>58<\/td><\/tr><\/table> <br\/> V\u1eadn t\u1ed1c trung b\u00ecnh c\u1ee7a t\u00e0u h\u1ecfa l\u00e0: <\/span>","select":["A. $56\\, km\/h$ ","B. $57\\, km\/h$ ","C. $58,5 \\, km\/h$","D. $57,5\\, km\/h$"],"explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/>L\u1eadp b\u1ea3ng t\u1ea7n s\u1ed1 v\u00e0 t\u00ednh s\u1ed1 trung b\u00ecnh c\u1ed9ng. <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> Ta c\u00f3 b\u1ea3ng sau: <br\/> <table><tr><th>Gi\u00e1 tr\u1ecb $(x)$<\/th><th>55<\/th><th>56<\/th><th>57<\/th><th>58<\/th><th>59<\/th><th>60<\/th><th><\/th><\/tr><tr><td>T\u1ea7n s\u1ed1 $(n)$<\/td><td>2<\/td><td>1<\/td><td>2<\/td><td>2<\/td><td>1<\/td><td>2<\/td><td>$N=10$<\/td><\/tr><tr><td>C\u00e1c t\u00edch $(x.n)$<\/td><td>110<\/td><td>56<\/td><td>114<\/td><td>116<\/td><td>59<\/td><td>120<\/td><td>T\u1ed5ng: 575<\/td><\/tr><\/table> <br\/> V\u1eadn t\u1ed1c trung b\u00ecnh c\u1ee7a t\u00e0u h\u1ecfa l\u00e0: <br\/> $\\dfrac{575}{10}=57,5\\,\\,\\,\\left( km\/h \\right)$ <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 D.<\/span><\/span>","column":4}]}],"id_ques":980}],"lesson":{"save":0,"level":2}}