Question

A bell rings every 25 minutes while other bell rings every 30 minutes. If the bells rang together at 6
a.m., at what time will they ring together again?
A. 08:30 a.m B. 08:30 p.m C.09:00 a.m D.09:00 p.m

Answer 1

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The lcm of 16 and 30 is 240

16= 2 x2x2x2

30= 2x3 x5.

So LCM is 2 x2x2x2 x3x5 =240.

So after 240- minutes the TWO BELLS will ring at the same time.

During this period Bell -A would have rung 15- times and Bell-B would have rung 8- times.

Answer 2

Answer:

Option a) 08:30 a.m

Considering the situation of option a)

from 6 a.m to 8:30 a.m

the difference is 2:30 hours

that is 150 mins

and

150/25=6

150/30=5

both are divisible as well