Question

Two trains leave the same station at the same time

and travel in opposite directions. One train travels
at 80 kilometers per hour and the other at 100
kilometers per hour. In how many hours will they
be 900 kilometers apart?

2 hours
3 hours
4 hours
5 hours

Answer 1

D. 5 hours

Explanation:

rt=d

rt+rt=900

80t+100t=900

180t=900

18t=90

2t=10

t=5

5 hours

80*5+100*5=900