Question

Two drivers moving in opposite directions on an 18-mile circular racetrack cross each other at a certain point. If one of them has an average speed of 1.2 miles per minute and the other has an average speed of 1.8 miles per minute, how many minutes will it take for them to cross each other again?

Answer 1

They both would cross each other again in the next 5 minutes

Explanation:

The first thing to do here is to calculate the lowest common multiple of the average speed of both drivers.

That would be the lowest common multiple of 1.2 miles per minute and 1.8 miles per minute.

That would be 3.6 miles per minute.

Now to get the time at which they would cross each other again, we simply divide the total distance around the circular track by the lowest common multiple of their average speed.

That would be 18/3.6 = 5

This means they would cross each other again in the next 5 minutes