A family decides to have 20 children. Find the probability of:
a) no girls
b)exactly 19 boys
c)at least 1 girl
d) at most 1 boy
please help and show your work or atleast explain how i can arrive at the answer
Lets assume X~Binomial(n=no of trials, p= probability of success)
The binomial theorem states
In your case lets call X the probability of having a girl with and
a) find
b) exactly 19 boys = exactly 1 girl so find
c) "at least 1" means 1 or more so find
Remember
d) "at most 1" means 1 or less so this means 2 or more girls now find