Question

A and B walk around a circular track. They start at 8
a.m. from the same point in the opposite directions.
A and B walk at a speed of 2 rounds per hour and 3
rounds per hour respectively. How many times shall
they cross each other before 9.30 a.m.?​

Answer 1

Relative speed = (2 + 3) km/hr = 5 km/hr This means that A and B cross each other 5 times in a hour and at least 2 times in half an hour

∴ They cross each other 7 times before 9:30 a.m.