So essentially these people have made a right triangle. The hypotenuse is going to be the distance from Bill to Ron.
Let's abbreviate B for Bill, J for John, and R for Ron.
J -> R = 30 yds
J -> B = 40 yds
These two lengths are the legs of the right triangle.
B -> R = hypotenuse of the right triangle.
Let's find the distance from B to R using the Pythagorean Theorem:





We now know that the hypotenuse is 50 yds.
The question wants to know the distance from R -> B (50 yds) and B -> J (40 yds). Let's add those together to get the total distance the football traveled:

The football traveled
90 yds total.