Six bells commence tolling together and toll at intervals of 2,4,6,8,10 and 12 seconds respectively. in 30 m9nutes,how many times do they toll together ? Choices:
A) 4
B) 10
C) 15
D) 16
E) 17
Solution   L.C.M. of 2,4,6,8,10,12 is 120.   So, the bells will toll together after every 120 seconds, i.e., 2 minutes   In 30 minutes, they will toll together left [   ( 30/2 )+ 1= 
<gadget id="calculator">  ( 30/2 )+ 1</gadget>
<output>16</output>
16 times. Answer 16
<result>D</result>
Six bells commence tolling together and toll at intervals of 2,4,6,8,10 and 12 seconds respectively. in 30 m9nutes,how many times do they toll together ?