Distance= rate times time problem

Question

Kylie and Katie both leave the library at the same time, but in opposite directions. If Katie travels 6 mph faster than Kylie and after 4 hours they are 72 miles apart, how fast is each traveling?

Answer 1

V(Katie) = V(Kylie) + 6

Total Distance between them = 72 = [V(Kylie) x V(Katie)] x 4

Hence. the sum of their velocities is 72/4 = 18

From here, V(Kylie) = 6 mph, V(Katie) = 6+6 = 12 mph.