Question

Six archers shoot arrows at a target at an interval of 4, 5, 6, 8, 10 and 12 seconds respectively. The number of times they would shoot the arrows together at the target in an hour is:
A) 10
B) 30
C) 15
D) 20

Answer 1

LCM of 4, 5, 6, 8, 10 and 12 seconds is 120 seconds

120 seconds = 2 minutes

1 hour/2 minutes = 60/2 = 30

So, (B)30 times they will shoot together at the target in an hour.