A woman drove her car on a road running due north at a given rate for 6 hours. She continued her trip on an unsaved road due east for 5 hours at a rate of 4mph slower. Had she been able to go to her destination in a straight line from her starting point and at her original rate she would have taken 71/2 hours. Find her rate for the first part of the journey.

1 answer

(6 x)^2 + [5 (x - 4)]^2 = (7.5 x)^2