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:
224 comments Page 23 of 23.
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.
Nahida Naaz said:
4 years ago
A -> 16
B -> 12.
Lcm -> 48.
Effi 3 and 4.
4 days work of (A+B) :- 4*7 = 28.
Total work - 4 days work of (A+B).
48- 28= 20.
Remaining work of 'C' will do in 4 days
So , 20/4 = 5.
Hence,
Whole work done by 'C'. 48/5.
B -> 12.
Lcm -> 48.
Effi 3 and 4.
4 days work of (A+B) :- 4*7 = 28.
Total work - 4 days work of (A+B).
48- 28= 20.
Remaining work of 'C' will do in 4 days
So , 20/4 = 5.
Hence,
Whole work done by 'C'. 48/5.
Harshal said:
4 years ago
First A=12.
and B=20.
Now the lcm of A and B is 60.
than A and B one day work is 7 and he's work together 7*4=28.
now the 28/60 forestation is 7*15.
and renaming work - total work 28-60=32.
Now 32/60= forestation us 8/15 answer.
and B=20.
Now the lcm of A and B is 60.
than A and B one day work is 7 and he's work together 7*4=28.
now the 28/60 forestation is 7*15.
and renaming work - total work 28-60=32.
Now 32/60= forestation us 8/15 answer.
Deekshit said:
3 years ago
Why the fraction 5/48 is changed to 48/5? Please explain.
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