Question

An electronic device makes a beep after every 60 seconds. Another device makes a beep after every 62 seconds. They beeped together at 10.00 a.m. The next time when they would beep together at the earliest one is:
1. 10.30 a.m.
2. 10.31 a.m.
3. 10.59 a.m.
4. 11.00 a.m.

Answer 1

Correct Answer - Option 2 : 10.31 a.m.

The Correct Answer is 10.31 a.m.

Given two device makes a beep after every 60 seconds and  62 seconds respectively.

Then LCM of 60 and 62 = 1860

60 Second = 1 minute 

1860 second = 31 minute.

Hence The device will beep after 31 minutes and the time will be 10.31 a.m.