Question

An electronic device makes a beep after every $60$ seconds. Another device makes a beep after every $62$ seconds. They beeped together at $10$a.m. At what time will they beep together at the earliest?

Answer 1

Given :
Beep Duration of first device $=60$ seconds
Beep Duration of Second device $=62$ seconds
To find the interval of beeping together , we need to find the LCM of $60$ and $62$ first.
$60=2\times 2\times 3\times 5$
$62=2\times 31$
LCM $=2\times 2\times 3\times 5\times 31=1860seconds$
Convert time into min
$160sec=\frac{1860}{60}$ mins $=31$ min
electronic devices will beep after very $31$ minutes.
hence , both device will together again beep at $10:31$ am again.