an electronic device makes a beep after every 60 seconds,another device makes a beep after every 62 seconds.they beep together at 10 am.the time when they will next make a veep together at the earliest is?
60 = 2*30
62 = 2*31
So, 31*60 = 30*62
That is the number of seconds that must elapse before they beep in synch again.
How many seconds is that? Then convert that to a time since 10:00.