Question

Wilson, Mathan and Guna can complete one round of a circular track in 10, 15 and 20 minutes respectively. If they start together at 7 a.m from the starting point, at what time will they meet together again at the starting point?

Answer 1

This is an LCM related problem

So, we need to find the LCM of 10, 15 and 20

5	10, 15, 20
2	2, 3, 4
	1, 3, 2

LCM = 5 × 2 × 1 × 3 × 2 = 60 min

They will meet together again after 60 minutes.

ie. 7 a.m + 60 minutes = 8 a.m