Aptitude - Problems on H.C.F and L.C.M - Discussion
Discussion Forum : Problems on H.C.F and L.C.M - General Questions (Q.No. 3)
3.
Six bells commence tolling together and toll at intervals of 2, 4, 6, 8 10 and 12 seconds respectively. In 30 minutes, how many times do they toll together ?
Answer: Option
Explanation:
L.C.M. of 2, 4, 6, 8, 10, 12 is 120.
So, the bells will toll together after every 120 seconds(2 minutes).
| In 30 minutes, they will toll together | 30 | + 1 = 16 times. |
| 2 |
Discussion:
171 comments Page 16 of 18.
Sunil said:
7 years ago
Just remember easily.
2,4,6,8,10,12.....take LCM, we get 120.
What they asking how many time toll together in 30 minutes
30minutes convert to seconds.
30*60=1800sec.
We have derived : 1800 ÷ 120=15.
At the time of zeroth sec tolls is 1 add total count 15+1=16.
2,4,6,8,10,12.....take LCM, we get 120.
What they asking how many time toll together in 30 minutes
30minutes convert to seconds.
30*60=1800sec.
We have derived : 1800 ÷ 120=15.
At the time of zeroth sec tolls is 1 add total count 15+1=16.
Anubhav verma said:
7 years ago
@All.
1 is added because in the question there is given that the bells start tolling together, so 1 toll is there at the 0th second and afterwards they toll at every 120th second.
1 is added because in the question there is given that the bells start tolling together, so 1 toll is there at the 0th second and afterwards they toll at every 120th second.
Pragati said:
7 years ago
Please anyone explain me again, I am not getting this.
Imran said:
7 years ago
Nice explanation @Saravan.
Praful said:
7 years ago
15 should be the correct answer.
because
if, it is asked that how many times clock hands have coincided then the answer is 22 not 23.
because
if, it is asked that how many times clock hands have coincided then the answer is 22 not 23.
Saanvi said:
7 years ago
Well said, Thanks @Sravanreddy.
Ashif said:
7 years ago
Excellent explanation. Thank you so much. @Sravan.
Orbis Roy said:
7 years ago
How to got 120 LCM? please explain me.
Shivam Tiwari said:
7 years ago
Why +1 is done in this can anyone say?
GSS said:
7 years ago
Thnaks @Sravanreddy.
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