Question

Aman, Anna and Tina are participating in the school race. Anna completes a lap in 120 minutes, Aman completes a lap in 240 minutes and Tina completes a lap in 60 minutes. If they all started at the same time, then after how long will they meet again?

Answer 1

Given:

Anna completes a lap in 120 minutes.

Aman completes a lap in 240 minutes

Tina completes a lap in 60 minutes.

To find:

The time after which they will meet again.

Solution:

They all started at the same time. So, the time after which they will meet again is the LCM of time taken by them to complete a lap.

Required time = LCM(120,240,60)

Factors of
`120 = 2* 2* 2* 3* 5`

Factors of
`240=2* 2* 2* 2* 3* 5`

Factors of
`60=2* 2* 3* 5`

So,

`LCM(120,240,60)=2* 2* 2* 2* 3* 5`

`LCM(120,240,60)=240`

Therefore, after 240 minutes they will meet again.