Answer:
:
Concept: 1 Mark
Steps: 2 Marks
Solution: 1 Mark
The given numbers are 2,4,6,8,10 and 12.
The factors of the given numbers are:
2=1$\times$2
2=2$\times$2
6=2$\times$3
8=2$\times$2$\times$2
10=2$\times$5
12=2$\times$2$\times$3
Now ,the maximum number of times prime factor 2 occurs is 3,
the maximum number of times prime factor 3 occurs is 1,
the maximum number of times prime factor 5 occurs is 1.
So, LCM=2$\times$2$\times$2$\times$3$\times$5 = 120
L.C.M. of 2, 4, 6, 8, 10 and 12 is 120.
So, the bells will toll together after every 120 seconds (2 minutes).
In 30 minutes, they will toll together $\frac{30}{2}$+ 1 = 16 times.