{"common":{"save":0,"post_id":"7424","level":3,"total":10,"point":10,"point_extra":0},"segment":[{"id":"5861","post_id":"7424","mon_id":"1158924","chapter_id":"1159182","question":"<p>Khi ph\u1ecfng v\u1ea5n các h\u1ecdc sinh c\u1ee7a m\u1ed9t l\u1edbp v\u1ec1 hai môn th\u1ec3 thao yêu thích là bóng \u0111á và \u0111á c\u1ea7u, k\u1ebft qu\u1ea3 thu \u0111\u01b0\u1ee3c có 20% h\u1ecdc sinh thích \u0111á c\u1ea7u, 35% h\u1ecdc sinh thích bóng \u0111á, 13% h\u1ecdc sinh thích c\u1ea3 hai môn bóng \u0111á và \u0111á c\u1ea7u. Ch\u1ecdn ng\u1eabu nhiên m\u1ed9t h\u1ecdc sinh c\u1ee7a l\u1edbp \u0111ó, tính xác su\u1ea5t \u0111\u1ec3 ch\u1ecdn \u0111\u01b0\u1ee3c m\u1ed9t h\u1ecdc sinh thích bóng \u0111á ho\u1eb7c \u0111á c\u1ea7u.<\/p>","options":["<strong>A. <\/strong>0,55","<strong>B. <\/strong>0,42","<strong>C. <\/strong>0,32","<strong>D. <\/strong>0,45"],"correct":"2","level":"3","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>B. <\/strong>0,42<\/span><\/p><p>G\u1ecdi A: “H\u1ecdc sinh thích \u0111á c\u1ea7u ”, ta có P(A) = 0,2.<\/p><p>B: “H\u1ecdc sinh thích bóng \u0111á” , ta có P(B) = 0,35.<\/p><p>A∩B: “H\u1ecdc sinh thích c\u1ea3 hai môn bóng \u0111á và \u0111á c\u1ea7u”, ta có P(A∩B) = 0,13.<\/p><p>A∪B: “H\u1ecdc sinh thích môn bóng \u0111á ho\u1eb7c môn \u0111á c\u1ea7u”.<\/p><p>Ta có: P(A∪B) = P(A) + P(B) – P(A∩B) = 0,2 + 0,35 – 0,13 = 0,42.<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2024-05-28 05:07:48","option_type":"txt","len":0},{"id":"5862","post_id":"7424","mon_id":"1158924","chapter_id":"1159182","question":"<p>Gieo m\u1ed9t con xúc s\u1eafc cân \u0111\u1ed1i \u0111\u1ed3ng ch\u1ea5t hai l\u1ea7n. Tính xác su\u1ea5t sao cho t\u1ed5ng s\u1ed1 ch\u1ea5m trong hai l\u1ea7n gieo là s\u1ed1 l\u1ebb.<\/p>","options":["<strong>A.<\/strong> 0,5","<strong>B.<\/strong> 0,9","<strong>C.<\/strong> 0,8","<strong>D.<\/strong> 0,6"],"correct":"1","level":"3","hint":"","answer":"<p>G\u1ecdi A là bi\u1ebfn c\u1ed1 "L\u1ea7n gieo \u0111\u1ea7u tiên xu\u1ea5t hi\u1ec7n \u0111\u01b0\u1ee3c m\u1eb7t ch\u1ea5m ch\u1eb5n".<br \/>B là bi\u1ebfn c\u1ed1 "L\u1ea7n gieo th\u1ee9 hai xu\u1ea5t hi\u1ec7n \u0111\u01b0\u1ee3c m\u1eb7t ch\u1ea5m ch\u1eb5n".<br \/>C là bi\u1ebfn c\u1ed1 "T\u1ed5ng s\u1ed1 ch\u1ea5m trong hai l\u1ea7n gieo là s\u1ed1 ch\u1eb5n".<\/p><p>⇒ C = AB ∪ <span class=\"math-tex\">$\\overline{AB}$<\/span>.<\/p><p>Do A và B là hai bi\u1ebfn c\u1ed1 \u0111\u1ed9c l\u1eadp nên<\/p><p>P(AB) = P(A).P(B) = <span class=\"math-tex\">$\\dfrac{1}{2}.\\dfrac{1}{2}$<\/span> = <span class=\"math-tex\">$\\dfrac{1}{4}$<\/span> và P(<span class=\"math-tex\">$\\overline{AB}$<\/span>) = P(<span class=\"math-tex\">$\\overline{A}$<\/span>).P(<span class=\"math-tex\">$\\overline{B}$<\/span>) = <span class=\"math-tex\">$\\dfrac{1}{2}.\\dfrac{1}{2}$<\/span> = <span class=\"math-tex\">$\\dfrac{1}{4}$<\/span>.<\/p><p>M\u1eb7t khác AB và <span class=\"math-tex\">$\\overline{AB}$<\/span> là hai bi\u1ebfn c\u1ed1 xung kh\u1eafc nên<\/p><p>P(C) = P(AB) + P(<span class=\"math-tex\">$\\overline{AB}$<\/span>) = <span class=\"math-tex\">$\\dfrac{1}{4}+\\dfrac{1}{4}$<\/span> = <span class=\"math-tex\">$\\dfrac{1}{2}$<\/span> = 0,5.<\/p><p>Xác su\u1ea5t \u0111\u1ec3 t\u1ed5ng s\u1ed1 ch\u1ea5m trong hai l\u1ea7n gieo là s\u1ed1 l\u1ebb là 1 – 0,5 = 0,5.<\/p><p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>A.<\/strong> 0,5.<\/span><\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2024-05-28 05:09:34","option_type":"txt","len":0},{"id":"5863","post_id":"7424","mon_id":"1158924","chapter_id":"1159182","question":"<p>Trong m\u1ed9t h\u1ed9p \u0111\u1ef1ng 6 bi xanh, 5 bi \u0111\u1ecf và 4 bi vàng, các viên bi khác nhau. L\u1ea5y ng\u1eabu nhiên 3 viên bi. Tính xác su\u1ea5t \u0111\u1ec3 3 viên bi l\u1ea5y ra cùng màu.<\/p>","options":["<strong>A. <\/strong><span class=\"math-tex\">$\\dfrac{17}{455}$<\/span>","<strong>B. <\/strong><span class=\"math-tex\">$\\dfrac{68}{455}$<\/span>","<strong>C. <\/strong><span class=\"math-tex\">$\\dfrac{34}{455}$<\/span>","<strong>D. <\/strong><span class=\"math-tex\">$\\dfrac{135}{455}$<\/span>"],"correct":"3","level":"3","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>C. <\/strong><span class=\"math-tex\">$\\dfrac{34}{455}$<\/span><\/span><\/p><p>S\u1ed1 ph\u1ea7n t\u1eed c\u1ee7a không gian m\u1eabu là <span class=\"math-tex\">$n(\\Omega)=C^3_{15}=455$<\/span>.<\/p><p>G\u1ecdi A: “L\u1ea5y ra 3 viên bi cùng màu xanh”, ta có n(A) = <span class=\"math-tex\">$C^3_6$<\/span> = 20 ⇒ P(A) = <span class=\"math-tex\">$\\dfrac{20}{455}$<\/span>.<\/p><p>B: “L\u1ea5y ra 3 viên bi cùng màu \u0111\u1ecf”, ta có n(B) = <span class=\"math-tex\">$C^3_5$<\/span> = 10 ⇒ P(B) = <span class=\"math-tex\">$\\dfrac{10}{455}$<\/span>.<\/p><p>C: “L\u1ea5y ra 3 viên bi cùng màu vàng”, ta có n(C) = <span class=\"math-tex\">$C^3_4$<\/span> = 4 ⇒ P(C) = <span class=\"math-tex\">$\\dfrac{4}{455}$<\/span>.<\/p><p>A∪B∪C: "L\u1ea5y ra 3 viên bi cùng màu" và các bi\u1ebfn c\u1ed1 A, B, C xung kh\u1eafc nhau.<\/p><p>P(A∪B∪C) = P(A) + P(B) + P(C) = <span style=\"color:#16a085;\"><span class=\"math-tex\">$\\dfrac{34}{455}$<\/span><\/span><\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2024-05-28 05:13:40","option_type":"math","len":0}]}