Question

21. There are six bells in a school. Six bells
commence tolling together and toll at intervals 2,
4, 6, 8, 10, 12 seconds respectively. In 20 min,
how many times do they toll together?
(a) 18 times (b) 12 times
(c) 11 times (d) 20 times
(e) none of these​

Answer 1

:lcm of 2,4,6,8,10,12 is 60

Hence after every 60 sec all the bells would ring together

20 min means 1200 sec

So 1200÷60=20 times

Hence d)20 is ur answer

Hope this helps u.....

Answer 2

Answer:

20

Step-by-step explanation: