Aptitude - Time and Work - Discussion
Discussion Forum : Time and Work - General Questions (Q.No. 9)
9.
A does 80% of a work in 20 days. He then calls in B and they together finish the remaining work in 3 days. How long B alone would take to do the whole work?
23 days
37 days
37
40 days
Answer: Option
Explanation:
| Whole work is done by A in |  |
20 x | 5 |  |
= 25 days. |
| 4 |
| Now, | |
1 - | 4 | |
i.e., | 1 | work is done by A and B in 3 days. |
| 5 | 5 |
Whole work will be done by A and B in (3 x 5) = 15 days.
| A's 1 day's work = | 1 | , (A + B)'s 1 day's work = | 1 | . |
| 25 | 15 |
 B's 1 day's work = |
|
1 | - | 1 | |
= | 4 | = | 2 | . |
| 15 | 25 | 150 | 75 |
| So, B alone would do the work in | 75 | = 37 | 1 | days. |
| 2 | 2 |
Discussion:
164 comments Page 14 of 17.
Nani said:
8 years ago
Good explanation, thank you @Rajendra.
Muna sharma said:
9 years ago
LCM of 15 and 25 is 150? Isn't it 75?
Reya said:
7 years ago
(1/15) - (1/25) how to simplify this?
Jeevesh said:
2 years ago
@Rajendra.
Thank you for explaining.
Thank you for explaining.
(4)
Nazeem said:
1 decade ago
Great explanation by baskar. Thanks.
Himanshu gawande said:
1 decade ago
A's 1 day work (1/80%)x20 = 25 days.
Nagendran said:
9 years ago
Can anyone explain B's 1 day's work?
Kannan said:
10 years ago
I don't understand please explain.
Sweety said:
8 years ago
Thanks for the explanation @Baskar.
Sky said:
9 years ago
Well explained, Thank you @Baskar.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers