一家汽车厂与两个供应商X和Y签订了购买减震器的合同。X提供60％的减震器，Y提供40％的减震器。所有减震器均经过质量测试。通过质量测试的被认为是可靠的。在X的减震器中，有96％是可靠的。在Y的减震器中，有72％是可靠的。
由Y得出的随机选择的减震器可靠的概率为
(A) 0.288
(B) 0.334
(丙) 0.667
(D) 0.720答案： (B)
解释：
Probability that the absorber is reliable = 0.96*0.6 + 0.72*0.4
= 0.576 + 0.288
Probability that the absorber is from y and reliable =
(Probability that is made by Y) X (Probability that it is reliable)
= 0.4 * 0.72
= 0.288
The probability that randomly picked reliable absorber is from y =
(Probability that the absorber is from y and reliable) / (>Probability that the absorber is reliable )
= (0.288)/ (0.576 + 0.288)
= 0.334 这个问题的测验