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:
172 comments Page 5 of 18.
Praful said:
8 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.
Imran said:
8 years ago
Nice explanation @Saravan.
Pragati said:
8 years ago
Please anyone explain me again, I am not getting this.
Anubhav verma said:
8 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.
Sunil said:
8 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.
Name said:
8 years ago
How 120 come?
Please explain.
Please explain.
Bhavadip Gothadiya said:
8 years ago
Anyone explain to me, why to add additional 1?
Why (30/2) +1 instead of (30/2)?
Why (30/2) +1 instead of (30/2)?
Yamini said:
8 years ago
Why 1 is added here? Please explain.
Avinash said:
8 years ago
Please explain in an easy way as why lcm method to be used?
Prasanth v said:
8 years ago
30/2=15.
And 15+1=16 (added +1 reason is first 0 to 2 sec bell is tolled at a time).
And 15+1=16 (added +1 reason is first 0 to 2 sec bell is tolled at a time).
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers