Question

two gongs strike at intervals of 14 and 77 minutes respectively. At what time will they strike together again if they start simultaneously at 12 noon?

Answer 1

Given :- Two gongs strike at intervals of 14 and 77 minutes respectively. At what time will they strike together again if they start simultaneously at 12 noon ?

Solution :-

we know that, two gongs strike together again after the time that is LCM of their individual time.

so, Prime factors 14 and 77 are :-

→ 14 = 2 * 7

→ 77 = 7 * 11

then,

→ LCM ÷ 2 * 7 * 11 = 154 minutes.

therefore,

→ Both gongs strike together again after = 154 minutes = 2 hours + 34 minutes .

hence,

→ they strike again together at = 12Noon + 2:34 = 2:34PM (Ans.)