wenchangfyc
幼苗
共回答了23个问题采纳率:87% 举报
射击三次先考虑甲只射中一次,则乙应该全不中:
甲三次可能为三次中任意一次,所以P=3乘以0.6乘以0.4乘以0.4乘以0.3乘以0.3乘以0.3=0.007766
如果中两次,则乙中一次或全部中.同样甲3次中任意有两次中.
p=3乘以0.6乘以0.6乘以0.4乘以0.3乘以0.3乘以0.3+3乘以0.6乘以0.4乘以0.4乘以3乘以0.7乘以0.3乘以0.3=0.011664+0.081648=0.093312
如果甲全中则乙中两次或一次或 全不中
P=0.6乘以0.6乘以0.6乘以0.3乘以0.3乘以0.3+0.6乘以0.6乘以0.6乘以3乘以0.7乘以0.3乘以0.3+0.6乘以0.6乘以0.6乘以3乘以0.7乘以0.7乘以0.3=0.005832+0.040824+0.085256=0.141912
所以总频率P=0.007766+0.093312+0.141912=0.24299约等于0.243
1年前
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