A newlywed couple wishes to have 3 children. What is the probability of having exactly 2 boys?

1 answer

prob(2boys of 3 children)
= C(3,2)(1/2)^2 (1/2)
= 3/8

or, you could list them:
BBB
BBG
BGB
BGG
GBB
GBG
GGB
GGG
There are 3 with 2 boys, 1 girl
prob(your event) = 3/8