Verbal Reasoning - Arithmetic Reasoning - Discussion
Discussion Forum : Arithmetic Reasoning - Section 1 (Q.No. 26)
26.
Five bells begin to toll together and toll respectively at intervals of 6, 5, 7, 10 and 12 seconds. How many times will they toll together in one hour excluding the one at the start ?
Answer: Option
Explanation:
L.C.M. of 6, 5, 7, 10 and 12 is 420.
So, the bells will toll together after every 420 seconds i.e. 7 minutes.
Now, 7 x 8 = 56 and 7 x 9 = 63.
Thus, in 1-hour (or 60 minutes), the bells will toll together 8 times, excluding the one at the start.
Discussion:
17 comments Page 2 of 2.
Priya said:
1 decade ago
How did we exclude the bell tolled at the first time while getting the answer as 8 times?
Sadi said:
1 decade ago
1 hour = 60 minutes.
1 minutes = 60 seconds.
So 60 minutes = 60*60 = 3600 seconds.
The last interval is 12 seconds so 3600/12 =300.
It will give the seconds of last bell ringing in sequence.
Now 300/3600*100 = 8.33.
So 8 minutes is the answer.
1 minutes = 60 seconds.
So 60 minutes = 60*60 = 3600 seconds.
The last interval is 12 seconds so 3600/12 =300.
It will give the seconds of last bell ringing in sequence.
Now 300/3600*100 = 8.33.
So 8 minutes is the answer.
Odyssey gohain said:
1 decade ago
If we had to find the answer considering the starting toll too. What would be the answer and how would we find out?
Nwialu samuel said:
1 decade ago
8 is the answer because 7* 8 does not exceed 60 mins but 7 * 9 exceeds 60 mins. So from this, 8 is the answer.
Ashish said:
1 decade ago
One hr means 60 min & according to given condition (how many times will they toll together in one hr excluding start one).
So they can toll together in one hr excluding start one is 8 times.
(Because one toll together in 7 min i.e. max toll together excluding start one is 60/7 = 8.57).
So they can toll together in one hr excluding start one is 8 times.
(Because one toll together in 7 min i.e. max toll together excluding start one is 60/7 = 8.57).
Ved Prakash said:
1 decade ago
I also want to know why 7*8 and 7*9 are multiplied ?
Purva said:
1 decade ago
Why multiply by 7*8 and so on? Please tel me.
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