Question

Four bells ring at intervals of 6,7 , 8 and 9 seconds respectively. All the bells will ring together after

a) 504 seconds b) 516 seconds

c 512 seconds c) 508 seconds

Answer 1

First We have to find LCM of 6, 7 , 8 and 9sec

6= 2×3
7=1×7
8= 2×2×2
9= 3× 3
L.C.M= 2×2×2×3×3×7= 504 sec

LCM of 6 seconds 7 seconds 8 seconds 9 seconds is = 504 seconds
In this type of question bell will ring at the Lcm time of all bells
Answer: bells will ring together after 504 seconds Ans A