College Finite Math
posted by Rory .
Suppose for this problem that Pr[E]=13/24 and Pr[F]=5/8
and Pr[(E U F)'] = 0. Finding Pr[E/F] and Pr[F/E].
For this problem I added 13/24 + 5/8 and got 1.17, therefore, I assumed that .17 is the intersection between Pr(E) and Pr(F). I know that to solve these problems I have to know the intersection and I know the basic formula is: Pr(E/F) = Pr(E intersected with F)/Pr(F) and vice versa.
Somewhere I am making a mistake. Can someone please help me solve this?

the answer is 8