You are given three facts :


    - The probability that an international flight leaving the United States is delayed in departing (event D) is 0.24.


    - The probability that an international flight leaving the United States is a transpacific flight (event P) is 0.50.


    - The probability that an international flight leaving the U.S. is a transpacific flight and is delayed in departing is .12.

          This event is the intersection of events D and P, so you are given the probability of intersection of these events

               P( D ∩ P ) = 0.12.


The problem's question asks about the conditional probability  P(D|P).


By the definition, for any two events P and D, the conditional probability  P(D|P) is this fraction

               P(D|P) = P ( D ∩ P ) / P(P).


Substitute the given data into this formula, and you will get


              P(D|P) =  = 0.24.


It is your ANSWER :   The probability that an international flight leaving the United States is delayed in departing 
                      given that the flight is a transpacific flight is 0.24.