Question

A passenger train and a freight train leave cities 260 mi apart and travel toward each other. The passenger train is traveling

15 mph faster than the freight train. Find the speed of each train if they pass each other after 4 hr.

Answer 1

Explanation:

x = speed of the passenger train

x - 15 = speed of the freight train

remember, the passenger train is traveling 15 mph faster than the freight train. that also means the freight train travels 15 mph slower than the passenger train.

we could define the variable also the other way around (x = freight train, x + 15 = passenger train).

speed = distance/time period

distance = speed × time period

so,

x×4 + (x - 15)×4 = 260

because when both trains meet somewhere in the middle, it means that the sum of both of their ways traveled is the whole distance between both cities : 260 miles.

4x + 4x - 60 = 260

8x = 320

x = 320/8 = 40 mph

so, the passenger train traveled at 40 mph.

the freight train traveled at 40-15 = 25 mph.