英语概率题求助!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
AstudentestimatesthattheprobabilityofhispassingChemistryorEnglishis0.8,theprobability...
A student estimates that the probability of his
passing Chemistry or English is 0.8, the probability
of his passing Chemistry is 0.7, but his
probability of passing both is 0.5. What should
be his estimate of the probability of his passing
English? 展开
passing Chemistry or English is 0.8, the probability
of his passing Chemistry is 0.7, but his
probability of passing both is 0.5. What should
be his estimate of the probability of his passing
English? 展开
2个回答
展开全部
P(A∪B)=P(A)+P(B)-P(A∩B)
If event A represents pass chem
event B represents pass Eng
then we have
P(A∪B)=0.8
因为是或的关系即,过化学或者过英语,即至少过一门即可
即过化学的事件发生+过英语的时间发生
=过化学的事件集并上过英语的事件集
=A∪B
P(A)=0.7
P(A∩B)=0.5
so the equation becomes
0.8=0.7+P(B)-0.5
P(B)=0.6
the probability of his passing
English is 0.6
If event A represents pass chem
event B represents pass Eng
then we have
P(A∪B)=0.8
因为是或的关系即,过化学或者过英语,即至少过一门即可
即过化学的事件发生+过英语的时间发生
=过化学的事件集并上过英语的事件集
=A∪B
P(A)=0.7
P(A∩B)=0.5
so the equation becomes
0.8=0.7+P(B)-0.5
P(B)=0.6
the probability of his passing
English is 0.6
推荐律师服务:
若未解决您的问题,请您详细描述您的问题,通过百度律临进行免费专业咨询