Train Rate

Question

Two trains leave the station at the same time, one heading west and the other east. The westbound train travels
10 miles per hour faster than the eastbound train. If the two trains are 720 miles apart after 4 hours, what is the rate of the westbound train?

Answer 1

distance=rate*time

total distance=rate*time(eastbound)+rate*time(westbound)

720=r*4+(r+10)*4

720=4r+4r+40

720=8r+40

720-40=8r

680=8r

r=680/8

r=85 mph eastbound

r+10=85+10=95 mph westbound

check:85*4+95*4=340+380=720 miles apart