Question

Five hells begin to toll together and toll respectively at intervals of 6, 7,8, 9 and 12 scconds. How many times they will toll together in one hour?

Answer 1

Answer:

Step-by-step explanation:

You have to find the common multiples that are not above 3600 (the seconds in one hour)  

6=2*3  

7=7  

8=2*2*2=2^3  

9=3*3=3^2  

12=2*2*3=2^2*3  

Lowest common multiple is: 2^3*3^2*7=504 They coincide at every 504 seconds  

They will bell toghether at 504, 1008, 1512, 2016, 2520, 3024 and 3528 seconds. The answer would be, then, they bell together 7 times in one hour, excluding the one at the start.

I hope you understand