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# Four bells toll at intervals of 2, 4, 8, 12 minutes respectively. If they start tolling together at 11 a.m. Find after what interval will they toll together and how many times they toll together in 8 hours.

 A) 6 times B) 7times C) 8 times D) 21 times

 D) 21 times

Description for Correct answer:
LCM of 2, 4, 8, 12 is 24 min.

$$\Large \frac{2,\ 4,\ 8,\ 12}{2} = 1,\ 2,\ 4,\ 3,$$

So they will toll together after 24 minutes.

In 8 hours, they will toll together

$$\Large \frac{480}{24}+1\ time\ at\ the\ start$$ = 21 times.

Part of solved LCM and HCF questions and answers : >> Elementary Mathematics >> LCM and HCF

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