On a circular track, Ishaan, Deepika and Tenzin take 36 s, 48 s and 60 s to complete one lap. They start together from the starting line. After how long will all three first be at the starting line together again?

Explanation

1. 01

   They meet at the start after LCM(36, 48, 60) seconds.

2. 02

   $36 = 2^2 \times 3^2$, $48 = 2^4 \times 3$, $60 = 2^2 \times 3 \times 5$.

3. 03

   LCM = $2^4 \times 3^2 \times 5 = 720$ $s = 12$ minutes.