Question

Two trains leave the station at the same time. One is traveling east at rate of 78mph. The other is traveling west at rate of 72 mph. How long to they have to travel until they are 1,162.5 miles apart?

Answer 1

The time the both trains have to travel for making a distance of 1162.5 miles apart T = 7.75 hour

Explanation:

Speed of the first train = 78
`(mi)/(h)`

Speed of the second train = 72
`(mi)/(h)`

Suppose the both trains have to travel for time = T hour

The distance traveled by first train (
`D_(1)` ) = Speed × time

⇒
`D_(1)` = 78 × T --------- (1)

The distance traveled by second train (
`D_(2)` ) = 72 × T --------- (2)

Total distance D =
`D_(1)` +
`D_(2)`

⇒ D = 78 × T + 72 × T

⇒ 1162.5 = 150 T

⇒ T = 7.75 hour

This is the time the both trains have to travel for making a distance of 1162.5 miles apart.