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 12 of 23.
Tiny said:
1 decade ago
@chandrakant.
Your method is totaly wrong. When c comes in right hand side it will become negative.
Your method is totaly wrong. When c comes in right hand side it will become negative.
Udita said:
1 decade ago
@Saquib Ali.
Please explain the following step.
Units of work in a day by a = 48x/16 = 48 units.
Please explain the following step.
Units of work in a day by a = 48x/16 = 48 units.
Khan said:
1 decade ago
A's 1 day work is 1/16.
B's 1 day work is 1/12. As given.
That means C's 5 days work is 5/48 na?
B's 1 day work is 1/12. As given.
That means C's 5 days work is 5/48 na?
Disha said:
5 years ago
5/48 of the whole work is done in one day. Then one whole work is;
5/48:1::1:x.
1*1/[5/48] = 48/5.
5/48:1::1:x.
1*1/[5/48] = 48/5.
Neelam said:
1 decade ago
Thanks uthaap, I was confused about the cross multiplication. Now you explained in easy manner.
Hasan Ali Tariq said:
1 decade ago
@Carlo.
I think Carlo explain it nicely and simply. The issue of inverse value 5/48 to 48/5.
I think Carlo explain it nicely and simply. The issue of inverse value 5/48 to 48/5.
Anusha said:
1 decade ago
I didn't get clearly that how 5/48 is reversed? can anyone help me for better understanding?
Shweta Narkhede said:
9 years ago
Thank you very much friends, I got lots of help because of yours discussion with this topic.
Leena said:
1 decade ago
One day's work is 5/48.
But we want number of days that 'C' alone can do, so 48/5 days.
But we want number of days that 'C' alone can do, so 48/5 days.
Gunjan said:
4 years ago
A-15.
B-20.
1/15 + 1/20 = 7/60.
7/60 x 4= 28/60 = 14/30 = 7/15.
( 1 - 7/15 ) = 8/15.
B-20.
1/15 + 1/20 = 7/60.
7/60 x 4= 28/60 = 14/30 = 7/15.
( 1 - 7/15 ) = 8/15.
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