Question

Four whistles blow at intervals of 6, 8 , 12, and 18 seconds. They start blowing simultaneously at 12 o ’clock. In how much time will they blow again simultaneously?

Answer 1

Solution:

Four Whistles blow at intervals of 6, 8 , 12, and 18 seconds.

Time after the whistle will blow again= H.C.F of 6,8,12,18.

6 = 2 × 3

8 = 2×2×2

12= 2×2×3

18 =2×3×3

H.C.F(6,8,12,18)= 2×3×2×2×3=72

After 72 seconds the whistle will blow again.

So if Four whistle have blown at 12 'o clock it will blow after 72 seconds=After 1 minute 12 seconds i.e 12:01 minute 12'seconds.