{"common":{"save":0,"post_id":"6710","level":3,"total":10,"point":10,"point_extra":0},"segment":[{"id":"7358","mon_id":"1158769","chapter_id":"1158999","post_id":"6710","question":"<p>Trên giá sách có 4 quy\u1ec3n sách toán, 3 quy\u1ec3n sách lý, 2 quy\u1ec3n sách hóa. L\u1ea5y ng\u1eabu nhiên 3 quy\u1ec3n sách. Tính xác su\u1ea5t \u0111\u1ec3 trong ba quy\u1ec3n sách l\u1ea5y ra có ít nh\u1ea5t m\u1ed9t quy\u1ec3n là toán.<\/p>","options":["<strong>A.<\/strong> <span class=\"math-tex\">$\\dfrac{2}{7}$<\/span>","<strong>B.<\/strong> <span class=\"math-tex\">$\\dfrac{3}{4}$<\/span>","<strong>C.<\/strong> <span class=\"math-tex\">$\\dfrac{37}{42}$<\/span>","<strong>D.<\/strong> <span class=\"math-tex\">$\\dfrac{10}{21}$<\/span>"],"correct":"3","level":"3","hint":"","answer":"<p>S\u1ed1 k\u1ebft qu\u1ea3 có th\u1ec3 khi ch\u1ecdn b\u1ea5t kì 3 quy\u1ec3n sách trong 9 quy\u1ec3n sách là <span class=\"math-tex\">$C_9^3=84$<\/span>.<\/p><p>G\u1ecdi A là bi\u1ebfn c\u1ed1 "L\u1ea5y \u0111\u01b0\u1ee3c ít nh\u1ea5t 1 sách toán trong 3 quy\u1ec3n sách".<\/p><p><span class=\"math-tex\">$\\overline{A}$<\/span> là bi\u1ebfn c\u1ed1 "Không l\u1ea5y \u0111\u01b0\u1ee3c sách toán trong 3 quy\u1ec3n sách".<\/p><p>Ta có xác su\u1ea5t \u0111\u1ec3 bi\u1ebfn c\u1ed1 A x\u1ea3y ra là P(A) = 1 – P(<span class=\"math-tex\">$\\overline{A}$<\/span>) = 1 – <span class=\"math-tex\">$\\dfrac{C_5^3}{84}=\\dfrac{37}{42}$<\/span><\/p><p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>C.<\/strong> <span class=\"math-tex\">$\\dfrac{37}{42}$<\/span><\/span><\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2023-09-24 04:37:53","option_type":"math","len":0},{"id":"7361","mon_id":"1158769","chapter_id":"1158999","post_id":"6710","question":"<p>G\u1ecdi S là t\u1eadp h\u1ee3p các s\u1ed1 t\u1ef1 nhiên có 4 ch\u1eef s\u1ed1 khác nhau \u0111\u01b0\u1ee3c t\u1ea1o t\u1eeb t\u1eadp {1; 2; 3; 4; 5}. Ch\u1ecdn ng\u1eabu nhiên m\u1ed9t s\u1ed1 t\u1eeb t\u1eadp S. Tính xác su\u1ea5t \u0111\u1ec3 s\u1ed1 \u0111\u01b0\u1ee3c ch\u1ecdn là m\u1ed9t s\u1ed1 ch\u1eb5n.<\/p>","options":["<strong>A.<\/strong> <span class=\"math-tex\">$\\dfrac{3}{4}$<\/span>","<strong>B.<\/strong> <span class=\"math-tex\">$\\dfrac{2}{5}$<\/span>","<strong>C.<\/strong> <span class=\"math-tex\">$\\dfrac{3}{5}$<\/span>","<strong>D.<\/strong> <span class=\"math-tex\">$\\dfrac{1}{2}$<\/span>"],"correct":"2","level":"3","hint":"","answer":"<p>S\u1ed1 ph\u1ea7n t\u1eed c\u1ee7a không gian m\u1eabu là: <span class=\"math-tex\">$n(\\Omega)=A_5^4=120$<\/span>.<\/p><p>G\u1ecdi A là bi\u1ebfn c\u1ed1 "S\u1ed1 \u0111\u01b0\u1ee3c ch\u1ecdn là s\u1ed1 ch\u1eb5n".<\/p><p>G\u1ecdi s\u1ed1 có 4 ch\u1eef s\u1ed1 khác nhau là <span class=\"math-tex\">$\\overline{abcd}$<\/span>.<\/p><p>+ Vì là s\u1ed1 ch\u1eb5n nên d có 2 cách ch\u1ecdn (d ∈ {2; 4}).<\/p><p>+ Các ch\u1eef s\u1ed1 còn l\u1ea1i có <span class=\"math-tex\">$A^3_4$<\/span> cách ch\u1ecdn.<\/p><p>Theo quy t\u1eafc nhân có 2 . <span class=\"math-tex\">$A^3_4$<\/span> = 48 s\u1ed1 th\u1ecfa yêu c\u1ea7u bài toán.<\/p><p>Suy ra n(A) = 48.<\/p><p>V\u1eady P(A) = <span class=\"math-tex\">$\\dfrac{n(A)}{n(\\Omega)}=\\dfrac{48}{120}=\\dfrac{2}{5}$<\/span><\/p><p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>B.<\/strong> <span class=\"math-tex\">$\\dfrac{2}{5}$<\/span><\/span><\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2023-09-27 01:18:11","option_type":"math","len":0},{"id":"7363","mon_id":"1158769","chapter_id":"1158999","post_id":"6710","question":"<p>Gieo m\u1ed9t con xúc x\u1eafc cân \u0111\u1ed1i \u0111\u1ed3ng ch\u1ea5t m\u1ed9t l\u1ea7n. Xác su\u1ea5t \u0111\u1ec3 xu\u1ea5t hi\u1ec7n m\u1eb7t ch\u1eb5n là:<\/p>","options":["<strong>A.<\/strong> <span class=\"math-tex\">$\\dfrac{1}{2}$<\/span>","<strong>B.<\/strong> <span class=\"math-tex\">$\\dfrac{1}{6}$<\/span>","<strong>C.<\/strong> <span class=\"math-tex\">$\\dfrac{1}{4}$<\/span>","<strong>D.<\/strong> <span class=\"math-tex\">$\\dfrac{1}{3}$<\/span>"],"correct":"1","level":"3","hint":"","answer":"<p>Không gian m\u1eabu là <span class=\"math-tex\">$\\Omega$<\/span> = {1; 2; 3; 4; 5; 6}. Suy ra n(<span class=\"math-tex\">$\\Omega$<\/span>) = 6.<\/p><p>G\u1ecdi A là bi\u1ebfn c\u1ed1 "Con xúc x\u1eafc xu\u1ea5t hi\u1ec7n m\u1eb7t ch\u1eb5n". Suy ra n(A) = 3.<\/p><p>Xác su\u1ea5t c\u1ea7n tìm là P(A) = <span class=\"math-tex\">$\\dfrac{3}{6}=\\dfrac{1}{2}$<\/span><\/p><p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>A.<\/strong> <span class=\"math-tex\">$\\dfrac{1}{2}$<\/span><\/span><\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2023-09-27 01:22:35","option_type":"math","len":0}]}