{"segment":[{"part":[{"title":"Ch\u1ecdn <u>nh\u1eefng<\/u> \u0111\u00e1p \u00e1n \u0111\u00fang","title_trans":"Ch\u1ecdn \u0111\u01b0\u1ee3c nhi\u1ec1u \u0111\u00e1p \u00e1n","temp":"checkbox","correct":[["1","2","4"]],"list":[{"point":10,"img":"","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\/> H\u00e3y ch\u1ecdn nh\u1eefng nh\u1eadn x\u00e9t \u0111\u00fang v\u1edbi s\u1ed1 li\u1ec7u \u0111\u00e3 cho trong b\u1ea3ng tr\u00ean. <\/span>","hint":"","column":1,"number_true":3,"select":["A. S\u1ed1 c\u00e1c \u0111\u1ed9 cao kh\u00e1c nhau l\u00e0 $6$","B. C\u1ea7u th\u1ee7 cao nh\u1ea5t l\u00e0 $184cm$, c\u1ea7u th\u1ee7 th\u1ea5p nh\u1ea5t l\u00e0 $170cm$","C. S\u1ed1 c\u1ea7u th\u1ee7 c\u1ee7a \u0111\u1ed9i b\u00f3ng \u0111\u00f3 l\u00e0 $20$","D. Chi\u1ec1u cao ph\u1ed5 bi\u1ebfn nh\u1ea5t l\u00e0 $178cm;180cm$"],"explain":"<span class='basic_left'>T\u1eeb b\u1ea3ng s\u1ed1 li\u1ec7u, ta c\u00f3 b\u1ea3ng ''t\u1ea7n s\u1ed1'' sau: <br\/> <table><tr><th>Gi\u00e1 tr\u1ecb $(x)$<\/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\/> - S\u1ed1 c\u00e1c \u0111\u1ed9 cao kh\u00e1c nhau l\u00e0 $6$ <br\/> $\\Rightarrow$ A \u0111\u00fang. <br\/> - C\u1ea7u th\u1ee7 cao nh\u1ea5t l\u00e0 $184cm$, c\u1ea7u th\u1ee7 th\u1ea5p nh\u1ea5t l\u00e0 $170cm$ <br\/> $\\Rightarrow$ B \u0111\u00fang. <br\/> - S\u1ed1 c\u1ea7u th\u1ee7 c\u1ee7a \u0111\u1ed9i b\u00f3ng \u0111\u00f3 l\u00e0 $18$ <br\/> $\\Rightarrow$ C sai. <br\/> - Chi\u1ec1u cao ph\u1ed5 bi\u1ebfn nh\u1ea5t l\u00e0 $178cm;180cm$ <br\/> $\\Rightarrow $ D \u0111\u00fang. <br\/> <span class='basic_pink'>Do \u0111\u00f3 c\u00f3 ba kh\u1eb3ng \u0111\u1ecbnh \u0111\u00fang l\u00e0 A, B v\u00e0 D.<\/span> <\/span>"}],"id_ques":1041},{"title":"\u0110i\u1ec1n c\u00e1c s\u1ed1 th\u00edch h\u1ee3p v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"\u0110\u1ec1 chung cho hai c\u00e2u","temp":"fill_the_blank","correct":[[["40"]]],"list":[{"point":10,"width":50,"content":"","type_input":"","ques":"<span class='basic_left'> \u0110i\u1ec3m ki\u1ec3m tra h\u1ecdc k\u00ec I m\u00f4n L\u1ecbch s\u1eed c\u1ee7a m\u1ed9t l\u1edbp \u0111\u01b0\u1ee3c cho trong b\u1ea3ng sau: <br\/> <table><tr><th>Gi\u00e1 tr\u1ecb $(x)$<\/th><th>5<\/th><th>7<\/th><th>8<\/th><th>9<\/th><th>10<\/th><th><\/th><\/tr><tr><td>T\u1ea7n s\u1ed1 $(n)$<\/td><td>6<\/td><td>12<\/td><td>12<\/td><td>8<\/td><td>2<\/td><td>$N$<\/td><\/tr><\/table> <br\/> <b> C\u00e2u a. <\/b> T\u00ednh $N.$ <br\/> <b> \u0110\u00e1p \u00e1n: <\/b> $N=\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}$ <\/span> ","hint":"S\u1ed1 c\u00e1c gi\u00e1 tr\u1ecb $N$ b\u1eb1ng t\u1ed5ng t\u1ea7n s\u1ed1 c\u1ee7a c\u00e1c gi\u00e1 tr\u1ecb kh\u00e1c nhau.","explain":"<span class='basic_left'> Theo b\u1ea3ng ''t\u1ea7n s\u1ed1'' \u0111\u1ec1 b\u00e0i \u0111\u00e3 cho, ta c\u00f3: <br\/> $N=6+12+12+8+2=40$<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":1042},{"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":[[4]],"list":[{"point":10,"ques":" <span class='basic_left'> \u0110i\u1ec3m ki\u1ec3m tra h\u1ecdc k\u00ec I m\u00f4n L\u1ecbch s\u1eed c\u1ee7a m\u1ed9t l\u1edbp \u0111\u01b0\u1ee3c cho trong b\u1ea3ng sau: <br\/> <table><tr><th>Gi\u00e1 tr\u1ecb $(x)$<\/th><th>5<\/th><th>7<\/th><th>8<\/th><th>9<\/th><th>10<\/th><th><\/th><\/tr><tr><td>T\u1ea7n s\u1ed1 $(n)$<\/td><td>6<\/td><td>12<\/td><td>12<\/td><td>8<\/td><td>2<\/td><td>$N$<\/td><\/tr><\/table> <br\/> <b> C\u00e2u b. <\/b> M\u1ed1t c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0: <\/span> ","select":["A. $10$ ","B. $12$","C. $8$ ","D. $7$ v\u00e0 $8$ "],"hint":"M\u1ed1t c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0 gi\u00e1 tr\u1ecb c\u00f3 t\u1ea7n s\u1ed1 l\u1edbn nh\u1ea5t.","explain":" <span class='basic_left'> Theo b\u1ea3ng ''t\u1ea7n s\u1ed1'' \u0111\u1ec1 b\u00e0i \u0111\u00e3 cho, ta th\u1ea5y: <br\/> + Gi\u00e1 tr\u1ecb $7$ c\u00f3 t\u1ea7n s\u1ed1 l\u1edbn nh\u1ea5t l\u00e0 $12$ <br\/> + Gi\u00e1 tr\u1ecb $8$ c\u00f3 t\u1ea7n s\u1ed1 l\u1edbn nh\u1ea5t l\u00e0 $12$ <br\/> Do \u0111\u00f3, m\u1ed1t c\u1ee7a d\u1ea5u hi\u1ec7u l\u00e0 $7$ v\u00e0 $8.$<br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":4}],"id_ques":1043},{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":10,"ques":" <span class='basic_left'> M\u1ed9t xe \u00f4 t\u00f4 ch\u1ea1y qu\u00e3ng \u0111\u01b0\u1eddng $AB$ trong $5$ gi\u1edd (kh\u00f4ng k\u1ec3 ngh\u1ec9). Hai gi\u1edd \u0111\u1ea7u xe ch\u1ea1y v\u1edbi v\u1eadn t\u1ed1c $60km\/h.$ Gi\u1edd th\u1ee9 ba xe ch\u1ea1y v\u1edbi v\u1eadn t\u1ed1c $70km\/h.$ Hai gi\u1edd cu\u1ed1i xe ch\u1ea1y v\u1edbi v\u1eadn t\u1ed1c $50km\/h.$ T\u00ednh v\u1eadn t\u1ed1c trung b\u00ecnh c\u1ee7a \u00f4 t\u00f4 tr\u00ean qu\u00e3ng \u0111\u01b0\u1eddng $AB.$ <\/span> ","select":["A. $58km\/h$ ","B. $55km\/h$","C. $60km\/h$ ","D. $62km\/h$ "],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/>L\u1eadp b\u1ea3ng ''t\u1ea7n s\u1ed1'' <br\/> S\u1eed d\u1ee5ng c\u00f4ng th\u1ee9c t\u00ednh trung b\u00ecnh c\u1ed9ng: <br\/> $\\overline{X}=\\dfrac{{{x}_{1}}{{n}_{1}}+{{x}_{2}}{{n}_{2}}+{{x}_{3}}{{n}_{3}}+.....+{{x}_{k}}{{n}_{k}}}{N}$ <br\/> Trong \u0111\u00f3: <br\/> ${{x}_{1}};{{x}_{2}};...;{{x}_{k}}$ l\u00e0 $k$ gi\u00e1 tr\u1ecb kh\u00e1c nhau c\u1ee7a d\u1ea5u hi\u1ec7u $X$ <br\/> $n_1;{{n}_{2}};...;{{n}_{k}}$ l\u00e0 $k$ t\u1ea7n s\u1ed1 t\u01b0\u01a1ng \u1ee9ng <br\/> $N$ l\u00e0 s\u1ed1 c\u00e1c gi\u00e1 tr\u1ecb <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> Ta c\u00f3 b\u1ea3ng sau: <br\/> <table><tr><th>V\u1eadn t\u1ed1c $(x)$<\/th><th>Th\u1eddi gian $(n)$<\/th><th>Qu\u00e3ng \u0111\u01b0\u1eddng $(x.n)$<\/th><th><\/th><\/tr><tr><td>60<\/td><td>2<\/td><td>120<\/td><td><\/td><\/tr><tr><td>70<\/td><td>1<\/td><td>70<\/td><td><\/td><\/tr><tr><td>50<\/td><td>2<\/td><td>100<\/td><td><\/td><\/tr><tr><td><\/td><td>$N=5$<\/td><td>T\u1ed5ng: $290$<\/td><td>$\\overline{X}=\\dfrac{290}{5}=58\\,\\,(km\/h)$ <\/td><\/tr><\/table><br\/> V\u1eady v\u1eadn t\u1ed1c trung b\u00ecnh c\u1ee7a \u00f4 t\u00f4 tr\u00ean qu\u00e3ng \u0111\u01b0\u1eddng $AB$ l\u00e0 $58km\/h$<br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":4}],"id_ques":1044},{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":10,"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/bai24/lv3/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":1045},{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":10,"ques":" <span class='basic_left'> \u0110o chi\u1ec1u cao c\u1ee7a $85$ h\u1ecdc sinh (\u0111\u01a1n v\u1ecb \u0111o: cm) \u0111\u01b0\u1ee3c k\u1ebft qu\u1ea3 trong b\u1ea3ng sau: <br\/> <table><tr><th>Chi\u1ec1u cao $(x)$<\/th><th>T\u1ea7n s\u1ed1 $(n)$<\/th><\/tr><tr><td>$120-130$<\/td><td>10<\/td><\/tr><tr><td>$130-140$<\/td><td>20<\/td><\/tr><tr><td>$140-150$<\/td><td>30<\/td><\/tr><tr><td>$150-160$<\/td><td>20<\/td><\/tr><tr><td>$160-170$<\/td><td>5<\/td><\/tr><tr><td><\/td><td>$N=85$<\/td><\/tr><\/table> <br\/> Chi\u1ec1u cao trung b\u00ecnh c\u1ee7a s\u1ed1 h\u1ecdc sinh n\u00f3i tr\u00ean l\u00e0: <\/span> ","select":["A. $138\\,cm$ ","B. $140,5\\,cm$","C. $143,8\\,cm$ ","D. $145\\,cm$ "],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> B\u1ea3ng ''t\u1ea7n s\u1ed1'' cho trong b\u00e0i l\u00e0 b\u1ea3ng ''t\u1ea7n s\u1ed1'' d\u1ea1ng kho\u1ea3ng. Tr\u01b0\u1edbc h\u1ebft ta ph\u1ea3i t\u00ednh gi\u00e1 tr\u1ecb trung b\u00ecnh c\u1ee7a t\u1eebng kho\u1ea3ng b\u1eb1ng c\u00e1ch t\u00ednh trung b\u00ecnh c\u1ed9ng c\u1ee7a s\u1ed1 \u0111\u1ea7u v\u00e0 s\u1ed1 cu\u1ed1i c\u1ee7a kho\u1ea3ng \u0111\u00f3. <br\/> S\u1eed d\u1ee5ng c\u00f4ng th\u1ee9c t\u00ednh trung b\u00ecnh c\u1ed9ng: <br\/> $\\overline{X}=\\dfrac{{{x}_{1}}{{n}_{1}}+{{x}_{2}}{{n}_{2}}+{{x}_{3}}{{n}_{3}}+.....+{{x}_{k}}{{n}_{k}}}{N}$ <br\/> Trong \u0111\u00f3: <br\/> ${{x}_{1}};{{x}_{2}};...;{{x}_{k}}$ l\u00e0 $k$ gi\u00e1 tr\u1ecb kh\u00e1c nhau c\u1ee7a d\u1ea5u hi\u1ec7u $X$ <br\/> $n_1;{{n}_{2}};...;{{n}_{k}}$ l\u00e0 $k$ t\u1ea7n s\u1ed1 t\u01b0\u01a1ng \u1ee9ng <br\/> $N$ l\u00e0 s\u1ed1 c\u00e1c gi\u00e1 tr\u1ecb <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> Ta c\u00f3 b\u1ea3ng sau: <br\/> <table><tr><th>Chi\u1ec1u cao $(x)$<\/th><th>Gi\u00e1 tr\u1ecb trung b\u00ecnh<\/th><th>T\u1ea7n s\u1ed1 $(n)$<\/th><th>C\u00e1c t\u00edch (x.n)<\/th><th><\/th><\/tr><tr><td>$120-130$<\/td><td>125<\/td><td>10<\/td><td>1250<\/td><td><\/td><\/tr><tr><td>$130-140$<\/td><td>135<\/td><td>20<\/td><td>2700<\/td><td><\/td><\/tr><tr><td>$140-150$<\/td><td>145<\/td><td>30<\/td><td>4350<\/td><td><\/td><\/tr><tr><td>$150-160$<\/td><td>155<\/td><td>20<\/td><td>3100<\/td><td><\/td><\/tr><tr><td>$160-170$<\/td><td>165<\/td><td>5<\/td><td>825<\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><td>$N=85$<\/td><td>T\u1ed5ng: $12225$<\/td><td>$\\overline{X}=\\dfrac{12225}{85}=143,8\\,\\,\\left( cm \\right)$ <\/td><\/tr><\/table> <br\/> V\u1eady chi\u1ec1u cao trung b\u00ecnh c\u1ee7a s\u1ed1 h\u1ecdc sinh n\u00f3i tr\u00ean l\u00e0 $143,8\\,cm$<br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":4}],"id_ques":1046},{"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":10,"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\/>$\\begin{align} & \\overline{X}=\\dfrac{30.14+34.9+37.7+x.17+45.3}{50}=36 \\\\ & \\Leftrightarrow \\dfrac{1120+x.17}{50}=36 \\\\ & \\Rightarrow 1120+17x=1800 \\\\ & \\Leftrightarrow 17x=1800-1120 \\\\ & \\Leftrightarrow 17x=680 \\\\ & \\Leftrightarrow x=680:17=40 \\\\ \\end{align}$ <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":1047},{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["8"],["4"]]],"list":[{"point":10,"width":40,"content":"","type_input":"","ques":" B\u1ea3ng sau th\u1ed1ng k\u00ea \u0111i\u1ec3m s\u1ed1 m\u1ed9t b\u00e0i ki\u1ec3m tra c\u1ee7a $40$ h\u1ecdc sinh:<br\/> <table><tr><th>Lo\u1ea1i \u0111i\u1ec3m<\/th><th>4<\/th><th>5<\/th><th>6<\/th><th>7<\/th><th>8<\/th><th>9<\/th><th>10<\/th><th><\/th><\/tr><tr><td>T\u1ea7n s\u1ed1 $(n)$<\/td><td>1<\/td><td>0<\/td><td>$x$<\/td><td>15<\/td><td>10<\/td><td>$y$<\/td><td>2<\/td><td>$N=40$<\/td><\/tr><\/table> <br\/> Bi\u1ebft s\u1ed1 h\u1ecdc sinh \u0111\u1ea1t t\u1eeb \u0111i\u1ec3m $8$ tr\u1edf l\u00ean chi\u1ebfm t\u1ec9 l\u1ec7 $40\\%$. H\u00e3y t\u00ednh $x$ v\u00e0 $y$. <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>","hint":"T\u00ednh t\u1ed5ng s\u1ed1 h\u1ecdc sinh \u0111\u1ea1t t\u1eeb \u0111i\u1ec3m $8$ tr\u1edf l\u00ean, t\u1eeb \u0111\u00f3 t\u00ecm $y$.","explain":"<span class='basic_left'>S\u1ed1 h\u1ecdc sinh \u0111\u1ea1t t\u1eeb $8$ \u0111i\u1ec3m tr\u1edf l\u00ean l\u00e0: <br\/>$40\\cdot \\dfrac{40}{100}=16$ (h\u1ecdc sinh) <br\/>Ta c\u00f3: <br\/>$\\begin{align} & 10+y+2=16 \\\\ & \\Rightarrow y=16-10-2 \\\\ & \\Rightarrow y=4 \\\\ \\end{align}$ <br\/> M\u1eb7t kh\u00e1c: <br\/> $\\begin{align} & 1+0+x+15+10+4+2=40 \\\\ & \\Rightarrow x+32=40 \\\\ & \\Rightarrow x=40-32 \\\\ & \\Rightarrow x=8 \\\\ \\end{align}$ <br\/>V\u1eady $x = 8; y = 4$<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 $8;4$.<\/span><\/span>"}],"id_ques":1048},{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang nh\u1ea5t v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["2"],["5"],["2"],["4"],["3"],["12,5","12.5"],["31,25","31.25"],["12,5","12.5"],["25"],["18,75","18.75"]]],"list":[{"point":10,"width":50,"content":"","type_input":"","ques":"S\u1ed1 tu\u1ed5i c\u1ee7a $16$ c\u1ea7u th\u1ee7 trong m\u1ed9t \u0111\u1ed9i b\u00f3ng nh\u01b0 sau: <br\/><table><tr><th>18<\/th><th>18<\/th><th>21<\/th><th>18<\/th><th>19<\/th><th>20<\/th><th>20<\/th><th>21<\/th><\/tr><tr><td>18<\/td><td>17<\/td><td>19<\/td><td>20<\/td><td>20<\/td><td>21<\/td><td>18<\/td><td>17<\/td><\/tr><\/table> <br\/> \u0110i\u1ec1n v\u00e0o c\u00e1c \u00f4 tr\u1ed1ng trong b\u1ea3ng \u2018t\u1ea7n s\u1ed1\u2019 trong \u0111\u00f3 c\u00f3 t\u1ea7n su\u1ea5t (t\u00ednh theo $\\%$) c\u1ee7a m\u1ed7i gi\u00e1 tr\u1ecb sau: <br\/> <table><tr><th>Gi\u00e1 tr\u1ecb $(x)$<\/th><th>17<\/th><th>18<\/th><th>19<\/th><th>20<\/th><th>21<\/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>$N=16$<\/td><\/tr><tr><td>T\u1ea7n su\u1ea5t $(f)$<\/td><td>_input_%<\/td><td>_input_%<\/td><td>_input_%<\/td><td>_input_%<\/td><td>_input_%<\/td><td>100%<\/td><\/tr><\/table>","hint":"T\u1ea7n su\u1ea5t $f$ c\u1ee7a m\u1ed9t gi\u00e1 tr\u1ecb \u0111\u01b0\u1ee3c t\u00ednh theo c\u00f4ng th\u1ee9c $f=\\dfrac{n}{N}$ ($n$ l\u00e0 t\u1ea7n s\u1ed1 c\u1ee7a gi\u00e1 tr\u1ecb, $N$ l\u00e0 s\u1ed1 c\u00e1c gi\u00e1 tr\u1ecb) <br\/> - T\u1ea7n su\u1ea5t $f$ th\u01b0\u1eddng \u0111\u01b0\u1ee3c t\u00ednh d\u01b0\u1edbi d\u1ea1ng t\u1ec9 s\u1ed1 ph\u1ea7n tr\u0103m.","explain":"<span class='basic_left'> Ta c\u00f3 b\u1ea3ng \u2018t\u1ea7n s\u1ed1\u2019 \u0111\u1ea7y \u0111\u1ee7 nh\u01b0 sau: <br\/> <table><tr><th>Gi\u00e1 tr\u1ecb $(x)$<\/th><th>17<\/th><th>18<\/th><th>19<\/th><th>20<\/th><th>21<\/th><th><\/th><\/tr><tr><td>T\u1ea7n s\u1ed1 $(n)$<\/td><td>2<\/td><td>5<\/td><td>2<\/td><td>4<\/td><td>3<\/td><td>$N=16$<\/td><\/tr><tr><td>T\u1ea7n su\u1ea5t $(f)$<\/td><td>12,5%<\/td><td>31,25%<\/td><td>12,5%<\/td><td>25%<\/td><td>18,75%<\/td><td>100%<\/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 \u1edf h\u00e0ng t\u1ea7n s\u1ed1 $(n)$ l\u1ea7n l\u01b0\u1ee3t l\u00e0: $2;5;2;4;3$ <br\/> C\u00e1c s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o c\u00e1c \u00f4 tr\u1ed1ng \u1edf h\u00e0ng t\u1ea7n su\u1ea5t $(f)$ l\u1ea7n l\u01b0\u1ee3t l\u00e0 $12,5;\\,31,25;\\,12,5;\\,25;\\,18,75$<\/span> <\/span>"}],"id_ques":1049},{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":10,"ques":"<span class='basic_left'>M\u1ed9t h\u1ecdc sinh vi\u1ebft $27$ s\u1ed1 r\u1ed3i t\u00ednh trung b\u00ecnh c\u1ee7a ch\u00fang, nh\u01b0ng sau \u0111\u00f3 l\u1ea1i vi\u1ebft ti\u1ebfp s\u1ed1 trung b\u00ecnh c\u1ed9ng \u0111\u00f3 b\u00ean c\u1ea1nh r\u1ed3i t\u00ednh lu\u00f4n s\u1ed1 trung b\u00ecnh c\u1ed9ng c\u1ee7a $28$ s\u1ed1. S\u1ed1 trung b\u00ecnh c\u1ed9ng l\u00fac sau l\u1edbn h\u01a1n, nh\u1ecf h\u01a1n hay b\u1eb1ng s\u1ed1 trung b\u00ecnh c\u1ed9ng l\u00fac \u0111\u1ea7u (trung b\u00ecnh c\u1ed9ng c\u1ee7a $27$ s\u1ed1).<\/span>","select":["A. L\u1edbn h\u01a1n","B. Nh\u1ecf h\u01a1n","C. B\u1eb1ng"],"explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/>G\u1ecdi trung b\u00ecnh c\u1ed9ng c\u1ee7a $27$ s\u1ed1 l\u00fac \u0111\u1ea7u l\u00e0 $a$ <br\/> T\u00ecm t\u1ed5ng c\u1ee7a $27$ s\u1ed1 l\u00fac \u0111\u1ea7u theo $a$ <br\/> T\u00ednh trung b\u00ecnh c\u1ed9ng l\u00fac sau theo $a.$ <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>G\u1ecdi s\u1ed1 trung b\u00ecnh c\u1ed9ng l\u00fac \u0111\u1ea7u (trung b\u00ecnh c\u1ed9ng c\u1ee7a $27$ s\u1ed1) l\u00e0 $a.$ <br\/> T\u1ed5ng c\u1ee7a $27$ s\u1ed1 l\u00e0: $27a$ <br\/> S\u1ed1 trung b\u00ecnh c\u1ed9ng l\u00fac sau l\u00e0: $\\dfrac{27a+a}{28}=\\dfrac{28a}{28}=a$ <br\/> $\\Rightarrow$ S\u1ed1 trung b\u00ecnh c\u1ed9ng l\u00fac sau b\u1eb1ng s\u1ed1 trung b\u00ecnh c\u1ed9ng l\u00fac \u0111\u1ea7u. <br\/><span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 C.<\/span><\/span>","column":3}],"id_ques":1050}],"id_ques":0}],"lesson":{"save":1,"level":3,"time":44}}