Question

Two trains heading toward each other are 400 miles apart. One train travels 15 miles per hour faster than the other train. If they arrive at the same station in 5 hours, how fast is each train traveling?

Answer 1

time = distance over speed
since the time is the same for both trains, and their combined distance is 400,

d/s = (400-d)/(s+15) = 5
d = 5s, so

(400-5s)/(s+15) = 5
s = 32.5
d = 162.5

check: 162.5/32.5 = 5
237.5/47.5 = 5

Answer 2

100