Question

six Bells start tolling together and they toll at intervals of 2 4 6 8 10 12 seconds respectively find after how much time will all 6 of them toll together

Answer 1

easy question...
2 in to 60 = 120
4 in to 30=120
6 in to 20=120
8 in to 15=120
10 in to 12=120
12 in to 10=120
all bells ring together after 120 seconds

Answer 2

time when they will toll again= LCM of time intervals of all the six bells
=LCM of (2,4,6,8,10,12)
now spiltting into prime factors,
2=2×1
4=2×2
6=2×3
8=2×2×2×2
10=2×5
12=2×2×3
so the LCM of (2,4,6,8,10,12) is 2×2×2×3×5=120
Therefore they will toll together in 120 seconds