Verbal Reasoning - Arithmetic Reasoning - Discussion

They will toll together 8 times, including the start, then if we exclude its 8-1 =7 times.
Why the answer is 8 times.
Anyone, clarify to me.

Agree @Sushil Ojha.

Thank you for the explanation @Jaspreet Singh.

@Nidhi.

You are absolutely wrong.

How did you get LCM 336? :(LCM is 420 and answer is 8 times).

Thanks for explaining @Jaspreet Singh.

Ans is 9.
Lcm is 336.
Now 336 ÷ 60 is 5.6.
5.6 * 10 = 56.
Excluding first term, we get 9.

My question is, five balls begin to toll together and toll respectively at intervals of 6, 7, 8 and 12 seconds. How many times they will toll together in one hours excluding the one at the start?

A) 3.
B) 5.
C) 7.
D) 9.

Can anyone solve this?

What does it mean at the interval of 6, 5, 7, 10, 12 and why we are taking lcm?

Please explain it to me.

It tolls together 9 times.
It is;

1starting
2nd on 7
3rd on 14
4th on 21
5th on 28
6th on 35
7th on 42
8th on 49
9th on 56 minutes.

Five bells begin to toll together means: when they begin they toll together.

Then at intervals of 6, 5, 7, 10 and 12.

The only way to know when will they again toll together is by taking LCM (least common multiple).

LCM of 6, 5, 7, 10 and 12 is 420 seconds.

As 1 min = 60 seconds.

So 420/60 = 7 minutes.

So, the bells will toll together after every 7 minutes.

That means 1st at 7 minutes; next at 14 minutes; next at 21 minutes and so on.

Means in 1 hour if I want to calculate how many times then it will be 8 times.

As total time (60 mins) = no. of times X 1 time (7 minutes).

Or no. times they will toll together = Total time/1 time.

i.e 60/7 = 8 times (approx).

If it asks for including the beginning when they start to toll together; then it will be,

8 times + 1 time = 9 times (remember as question said that they start by tolling together then they toll in intervals of 6, 5, 7, 10 and 12 seconds).