发布网友
共2个回答
热心网友
1、可能出现的情况:112,113,114,121,122,123,124,131,132,133,134,141,142,143,144,211,212,213,214,221,223,224,231,232,234,241,242,243,244,311,312,313,314,321,322,323,324,331,332,334,341,342,343,344,411,412,413,414,421,422,423,424,431,432,433,434,441,442,443,
(1)概率为9/14
(2)概率为3/28
(3)概率为4/7
2.正品按次序排为12345678,次品按次序排为ab
(1)可能出现的情况:11,12,13,14,15,16,17,18,1a,1b,21,22,23,24,25,26,27,28,2a,2b,31,32,33,34,35,36,37,38,3a,3b,41,42,43,44,45,46,47,48,4a,4b,51,52,53,54,55,56,57,58,5a,5b,61,62,63,,65,66,67,68,6a,6b,71,72,73,74,75,76,77,78,7a,7b,81,82,83,84,85,86,87,88,8a,8b
所以概率为/125
(2)可能出现的情况:123,124,125,126,127,128,12a,12b,132,134,135,136,137,138,13a,13b,142,143,145,146,147,148,14a,14b,152,153,154,156,157,158,15a,15b,162,163,1,165,167,168,16a,16b,172,173,174,175,176,178,17a,17b,182,183,184,185,186,187,18a,18b,213,214,215,216,217,218,21a,21b,231,234,235,236,237,238,23a,23b,241,243,245,246,247,248,24a,24b,251,253,254,256,257,258,25a,25b,261,263,2,265,267,268,26a,26b,271,273,274,275,276,278,27a,27b,312,314,315,316,317,318,31a,31b,321,324,325,326,327,328,32a,32b,341,342,345,346,347,348,34a,34b,351,352,354,356,357,358,35a,35b,361,362,3,365,367,368,36a,36b,371,372,374,375,376,378,37a,37b,381,382,384,385,386,387,38a,38b,412,413,415,416,417,418,41a,41b,421,423,425,426,427,428,42a,42b,431,432,435,436,437,438,43a,43b,451,452,453,456,457,458,45a,45b,461,462,463,465,467,468,46a,46b,471,472,473,475,476,478,47a,47b,481,482,483,485,486,487,48a,48b,512,513,514,516,517,518,51a,51b,521,523,524,526,527,528,52a,52b,531,532,534,536,537,538,53a,53b,541,542,543,546,547,548,54a,54b,561,562,563,5,567,568,56a,56b,571,572,573,574,576,578,57a,57b,581,582,583,584,586,587,58a,58b,612,613,614,615,617,618,61a,61b,621,623,624,625,627,628,62a,62b,631,632,634,635,637,638,63a,63b,1,2,3,5,7,8,a,b,651,652,653,654,657,658,65a
,65b,671,672,673,674,675,678,67a,67b,681,682,683,684,685,687,68a,68b,712,713,714,715,716,718,71a,71b,721,723,724,725,726,728,72a,72b,731,732,734,735,736,738,73a,73b,741,742,743,745,746,748,74a,74b,751,752,753,754,756,758,75a,75b,761,762,763,7,765,768,76a,76b,781,782,783,784,785,786,78a,78b,812,813,814,815,816,817,81a,81b,821,823,824,825,826,827,82a,82b,831,832,834,835,836,837,83a,83b,841,842,843,845,846,847,84a,84b,851,852,853,854,856,857,85a,85b,861,862,863,8,865,867,86a,86b,871,872,873,874,875,876,87a,87b
所以概率为13/15
3可能出现的情况:01,02,03,04,05,10,12,13,14,15,20,21,23,24,25,30,31,32,34,35,40,41,42,43,45,50,51,52,53,54
他们的和为1,2,3,4,5,1,3,4,5,6,2,3,5,6,7,3,4,6,7,8,4,5,6,7,9,5,6,7,8,9
(1)概率为2/15
(2)概率为13/15
热心网友
第一题:
(1)P=1-C63/C83=1-20/56=36/56=9/14
(2)P=C61/C83=6/56=3/28
(3)P=1-4XC61/C83=1-4X6/56=32/56=4/7
第二题:
(1)P=(8/10)^3=/125
(2)P=C83/C103=56/120=7/15
第三题:
(1)P=2/C62=2/15
(2)P=1-2/C62=1-2/15=13/15
建议还是自己思考~