Aptitude - Time and Work - Discussion
Discussion Forum : Time and Work - General Questions (Q.No. 2)
2.
A can lay railway track between two given stations in 16 days and B can do the same job in 12 days. With help of C, they did the job in 4 days only. Then, C alone can do the job in:
Answer: Option
Explanation:
| (A + B + C)'s 1 day's work = | 1 | , |
| 4 |
| A's 1 day's work = | 1 | , |
| 16 |
| B's 1 day's work = | 1 | . |
| 12 |
 C's 1 day's work = |
1 | - |  |
1 | + | 1 |  |
= | |
1 | - | 7 | |
= | 5 | . |
| 4 | 16 | 12 | 4 | 48 | 48 |
| So, C alone can do the work in | 48 | = 9 | 3 | days. |
| 5 | 5 |
Discussion:
226 comments Page 10 of 23.
Shweta Narkhede said:
9 years ago
Thank you very much friends, I got lots of help because of yours discussion with this topic.
Sankalp said:
9 years ago
Hi, I have a doubt. Please clarify it.
After finding LCM why do we reverse the answer? (i.e why do we have 48/5 after getting LCM as 5/48).
After finding LCM why do we reverse the answer? (i.e why do we have 48/5 after getting LCM as 5/48).
Sudhanshu patra said:
10 years ago
@Ganesh.
Thanks for explaining the answer.
Thanks for explaining the answer.
Sidhartha said:
10 years ago
How it come 5/48? Please give a clear solution.
Mathivanan said:
10 years ago
Awesome answers the way of explaining is very excellent. Thank you all of you.
Ganesh said:
10 years ago
Total work is 48 units.
A can do work in 16 days.
It means A completes 3 units per day.
B can do work in 12 days.
It means B completes 4 units per day.
Now A and B is helped by C and completed work in 4 days.
It means A, B and C together doing 12 units per day.
It means A+B+C = 12.
Sub A and B values.
3+4+C = 12.
C = 5.
It means C completes 5 units per day.
For 48 units?
Answer: 48/5.
A can do work in 16 days.
It means A completes 3 units per day.
B can do work in 12 days.
It means B completes 4 units per day.
Now A and B is helped by C and completed work in 4 days.
It means A, B and C together doing 12 units per day.
It means A+B+C = 12.
Sub A and B values.
3+4+C = 12.
C = 5.
It means C completes 5 units per day.
For 48 units?
Answer: 48/5.
(1)
Prachi said:
10 years ago
Like a b c are doing work in four days then can we assume the approach like it.
1/16 + 1/12+x = 4.
So x = 41/48, work of c.
Please tell.
1/16 + 1/12+x = 4.
So x = 41/48, work of c.
Please tell.
Kumar said:
10 years ago
@Amit.
It is addition.
It is addition.
Dikesh said:
10 years ago
Hi all,
If we convert 5/48 can lead to decimal, normally we won't measure days of decimal, hence we have to reverse it simple that's it. I think all you guys understood this.
If we convert 5/48 can lead to decimal, normally we won't measure days of decimal, hence we have to reverse it simple that's it. I think all you guys understood this.
Abhishek said:
1 decade ago
A - 16 days | 3 unit/day
L. C. M of (16, 12, 4).
| | = 48.
B - 12 days |4 unit/day|.
| |.
C - ? |x unit/day|.
-------------------------------------------------.
(A+B+C) - 4 days | 12 unit/day |.
So, for C we get (12-3+4) = 5 unit/day.
If C can do 5 unit in 1 day, then 48 unit can be done in 48/5 = 9*3/5 days.
Guys this is the easiest way.
L. C. M of (16, 12, 4).
| | = 48.
B - 12 days |4 unit/day|.
| |.
C - ? |x unit/day|.
-------------------------------------------------.
(A+B+C) - 4 days | 12 unit/day |.
So, for C we get (12-3+4) = 5 unit/day.
If C can do 5 unit in 1 day, then 48 unit can be done in 48/5 = 9*3/5 days.
Guys this is the easiest way.
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