C
The answer is 1/8
Because Darrens probability is 5/8 and dena is 1/4 it looks confusing. It is first necessary to make sure both fractions have the same denominator because you'll be adding them so see what the leftover is, as that would be your answer.
To do that, the easiest way is to have 1/4 have a denominator of 8. To do that, you multiply 1/4 by 1, but one can be anything equivalent to 1. Multiply 1/4 by 2/2(which is 1) to get 2/8. Now you have the same denominator and can add 5/8 + 2/8 which equal 7/8. There is 1/8th left which is your answer as that is the probability the third person is driving
