question_answer

Six bells commence tolling together at intervals of 2, 4, 6, 8, 10, 12 seconds respectively. In 30 minutes how many times do they toll together?

A)  4                                

B)  10

C)  15                               

D)  16

Correct Answer: C

Solution :

 LCM of (2, 4, 6, 8, 10, 12 seconds) = 120 seconds = 2 minutes  In 30 minutes    15 times