Mary H. answered • 04/15/18

Patient, easily-understood Math Instructor

Mae,

This is a distance = rate x time problem. Let x be the number of hours they have to travel. The distance they travel going north is 50 x, going south is 72 x . The distance they are apart is 50 x + 72 x , and we want to know what is x when they are 17 km apart.

50x + 72 x = 17

122 x = 17

x = 17/122 hours X 60 min./hr. ∼8.4 sec.

Hope you followed all the steps.

Mary