Five bells commence tolling together and toll at intervals of 2, 4, 6, 8,10 seconds respectively. In 60 minutes, how many times do they toll together?  Choose one.
A) 41
B) 10
C) 31
D) 16
E) 17
L.C.M of 2,4,6,8,10 is 240. i.e after each 2 min they will toll together.So in 60 min they will toll 30 times.As they have initially tolled once,The answer will be  30+1= 
<gadget id="calculator"> 30+1</gadget>
<output>31</output>
31.   ANSWER:31
<result>C</result>
Five bells commence tolling together and toll at intervals of 2, 4, 6, 8,10 seconds respectively. In 60 minutes, how many times do they toll together?