Question

Six bells commence tolling together and toll at intervals of 2 4 6 9 10 and 12 seconds. In first 30 minutes how many times do they toll together?

Answer 1

Answer: 16

take lcm of 2,4,6,8,10,12 seconds

the outcome is 120seconds.

thats at 2mins once it rings.

in 30mins it will rings 15times together

in 0th second all bells rings together.

so ans is 15+1=16.

Comments

So 9 shouldn't be there in the question as the time interval

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yes ,my logic is correct for 8 only,
not for 9 may be some other logic satisfies the above puzzle