Two trains started at 7 AM from the same point. The first train travelled north at a speed of 90 km/h and the second tra...

Question

Two trains started at 7 AM from the same point. The first train travelled north at a speed of 90 km/h and the second train travelled south at a speed of 100 km/h. The time at which they were 190 km apart is ________ AM.

A. 9  B. 10  C. 11  D. 11:30

Accepted Answer

The trains are 570 km apart at 10 AM (option B). The two trains start from the same point and move in opposite directions (north and south). The separation between them increases at the combined rate of both speeds. Setting the combined separation equal to 190 km and solving for elapsed time gives the answer. Since they start at 7 AM, add the elapsed hours to find the clock time.