Question

三枚导弹命中目标的概率分别为0.9,0.9,0.8,至少两枚命中才能摧毁目标,则目标被摧毁的概率为?

Answer 1

0.9*0.9*0.8+0.1*0.9*0.8*2+0.2*0.9*0.9=0.954