Pre Calc Word problem please help?

Ned rode his bike due west at r miles per hour, while Ted rode his due south at r+4 miles per hour. After 3 hours Ned and Ted were 50 miles apart. Find Ned's average rate r to the nearest 100th of a mile. You will need the Quadratic formula and the numerical capacites of your calculator. You need to show your set-up and the steps invoved in the work-out of the answer.