Re: Probability of a couple having a boy child is 0.4. If a couple decides
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21 Aug 2023, 04:11
We are told to find the probability that at least one of the children is a female.
Since these are independent think (similar to the case of a coin flip, heads or tails) we can create two "sets" of events:
P(all boys)+P(at least 1 girl)=1
P(at least 1 girl)=1-p(all boys)
This will shorten the time on the problem considerably - there is only 1 possible combination for all boys rather than the 3 combos for at least 1 girl.
P(all boys)=(2/5)^3=8/125
1-(8/125)=117/125=0.936
Choice D is correct