Addie C. answered • 08/28/14

Tutor

5
(2)
Physics/Chemical-Biomedical Engineering Student at OU

Alrighty, so if the sum of the speeds of two trains in 721.8 mph, that means that (1) Train 1 + Train 2 = 721.8 mph.

Using the given information, we know that Train 1 is 10.2 mph faster than Train 2 ... This means that Train 1 travels at 10.2 times Train 2, or in other words (2) 10.2*Train 2 = Train 1. We can now plug this into equation (1) to solve for the speed of Train 2.

10.2*Train 2 + Train 2 = 721.8

Train 2 = 721.8 / 11.2 = (about) 64.45 mph

Plugging this value of Train 2 into equation (2)

10.2*Train 2 = Train 1

10.2 * 64.45 = (about) 657.39 mph

Thus, Train 1's speed is 657.39 and Train 2's is 64.45 mph.

We can check this by making sure 657.39 + 64.45 = 721.84 (which is only 0.04 off from 721.8).

Your answer will differ depending on how many digits you round to.

Hope this helps!