Question

three Bells toll at intervals of 9,12,15 minutes respectively. if they start tolling together after what time will the next toll together

Answer 1

Take the LCM of the 3 numbers,then we can get the time when they will toll together.


And that is,LCM(9,12,15)=180


They will toll together after 180 minutes or 3 hours.

Hope it helps.

Answer 2

To find LCM (9, 12, 15)

9 = 3 × 3

12 = 2 × 2 × 3

15 = 3 × 5

LCM (9, 12, 15) = 3 × 3 × 2 × 2 × 5

= 180 minutes

The bells will toll together after 180 minutes