There are 4 girls and 5 boys would like to go on school trip but there are onlyy 2 seats available.
a) calculate the probability that one girl and one boy will be chosen
ans P (BG)+ P(GB)=( 5/9 x 4/8 ) +( 4/9 x 5/8 )
b) if Sarah is one of the girls who want to go on the trip, what is the probabily of not choosing Sarah?
How to solve it?