The first time they will toll together is the LCM of numbers of 2, 4, 6, 8, 10, 12 Thus, after 120 seconds,they toll together. So, Number of times they toll in 120 seconds = 1 Number of time

Answer of this question

Six bells commence tolling together and toll at interval of 2,4,6,8,10&12 seconds respectively. In 30 minutes, how many times do they toll together?

Davneet Singh

The first time they will toll together is the LCM of numbers of 2, 4, 6, 8, 10, 12

LCM of 2, 4, 6, 8, 10, 12.png

Thus, after 120 seconds,they toll together.

So,

Number of times they toll in 120 seconds = 1

Number of times they toll in 2 minutes = 1

Number of times they toll in 1 minutes = 1/2

Number of times they toll in 30 minutes = 1/2 x 30 = 15

But, at the starting point (i.e. at 0th second), they tolled together,

So, Number of times they toll in 30 minutes = 15 + 1 = 16

Written on Nov. 2, 2016, 9:45 p.m.

Comment

Class 6