Question

21. Six bells commence tolling together and toll at intervals of 2, 4, 6, 8 10 and 12 seconds respectively. In 30 minutes, how many times do they toll together? (a) 4 (b) 10 (C) 15 (d) 16​

Answer 1

Step-by-step explanation:

Intervals they started rolling= 2,4,6,8,10 and 12 sec

LCM of 2,4,6,8,10,12= 2=1*2

4=2*2

6=3*2.

8= 2*2*2

10= 5*2

12=3*2*2

2*2*2*3*5= 120 seconds.

So, they toll together after every 120 seconds.

30 minutes is 1800 seconds.

1800÷120= 15

So, the answer is C) They will toll together 15 times in 30 minutes.