Question

In a call centre at New Delhi, it is observed that it gets a call
at an interval of every 10 minutes from California, at every
12 minutes from Texas, at the interval of 20 minutes from
Washington DC and after every 25 minutes it gets the call
from London. If in the early morning at 5:00 a.m. it has
recieved the calls simultaneously from all the four
destinations, then at what time will it receive the calls
simultaneously from all the places on the same day?
(a) 10:00 a.m.
(b) 3:00 a.m.
(c) 5:00 p.m.
(d) both (a) and (b)
.
.
need step by step explanation!!!​

Answer 1

Fristly we should find the common no. which is divisble by 10,12,20and 25 by LCM method

This no. is 300

So after every 300 mintute they came simultaneously. After 5 am it would come at 10 am and then 3 pm.

So Correct answer is (d) both a and b

HOPE IT WILL HELP YOU