At a firing range, three shooters are firing at their respective targets. The first, the second and the third shooter hit their target once every 4 seconds, 5 seconds, and 6 seconds, respectively. If all of them hit their targets together at 10:00 am, then at what time will they hit their targets together again?

Correct option is D

Given:

Firing time required by three shooters 3sec,5sec and 6 sec

All of them shot at 10:00a.m.

Formula Used:

HCF and LCM

Prime Factorization

Solution:

Next time to shoot at same time will be the LCM of 4,5 and 6 seconds

Prime factorization of 4, 5 and 6

4 = $$2^2$$​​

5 = 5

6 =$$2 \times 3$$​​

LCM = $$2^2 \times 3 \times 5$$ =  60seconds

So the next time they will shoot after 60 seconds or 1 minute i.e. 10:01a.m.