79 because you just have to carry a few number over
Given:
Nick has x toy race cars. This is one-third of what Bob has.
So, the number of Nick toys = one-third of what Bob has.
Let the Bob has y toys
So, we can write the following expression:

Solve for y, multiply both sides by (3):

So, the answer will be:
Bob has (3x) toy race cars.
The answer for number 2 is 1/4
He walked 3/8 of a mile this weekend. You multiply the numerator in 3/4 by the numerator in one half, and get a numerator of 3. You multiply the denominator of 3/4 by the denominator of 1/2, and get a denominator of 8