Question

please help me? picture attached:)

Answer 1

@Hero can you please help me?

Answer 2

@phi ?

Answer 3

probabilities are between 0 and 1. So you can toss out choice A

you can do this problem by saying there are 100 flights total
81 left on time. 69 of them arrive on time.
find the ratio.

or
Pr( A | B) = Pr( A n B)/Pr(B)