Aptitude - Time and Work - Discussion
Discussion Forum : Time and Work - Data Sufficiency 1 (Q.No. 1)
Directions to Solve
Each of the questions given below consists of a statement and / or a question and two statements numbered I and II given below it. You have to decide whether the data provided in the statement(s) is / are sufficient to answer the given question. Read the both statements and
- Give answer (A) if the data in Statement I alone are sufficient to answer the question, while the data in Statement II alone are not sufficient to answer the question.
- Give answer (B) if the data in Statement II alone are sufficient to answer the question, while the data in Statement I alone are not sufficient to answer the question.
- Give answer (C) if the data either in Statement I or in Statement II alone are sufficient to answer the question.
- Give answer (D) if the data even in both Statements I and II together are not sufficient to answer the question.
- Give answer(E) if the data in both Statements I and II together are necessary to answer the question.
1.
A and B together can complete a task in 7 days. B alone can do it in 20 days. What part of the work was carried out by A? | |
I. | A completed the job alone after A and B worked together for 5 days. |
II. | Part of the work done by A could have been done by B and C together in 6 days. |
Answer: Option
Explanation:
| B's 1 day's work = | 1 |
| 20 |
| (A+ B)'s 1 day's work = | 1 |
| 7 |
| I. (A + B)'s 5 day's work = | 5 |
| 7 |
| Remaining work = |  |
1 - | 5 |  |
= | 2 | . |
| 7 | 7 |
 |
2 | work was carried by A. |
| 7 |
II. is irrelevant.
Correct answer is (A).
Discussion:
20 comments Page 1 of 2.
Pandurang Mahadev Magar said:
3 years ago
But A also work during the first 5 days why that work is not considered as his part of the work? Anyone, please explain me.
(5)
Keshri said:
5 years ago
It's easily understandable;
A+B=7.
B=20.
After substituting A's efficiency is 13.
So, 1 is agreed.
A+B=7.
B=20.
After substituting A's efficiency is 13.
So, 1 is agreed.
(4)
Shubham Nale said:
5 years ago
A+B takes 7 days to complete the whole work.
B takes 20 days.
Total work = LCM = 140,
A+B =20 unit/day.
For 5 days =100 unit work is done.
Therefore, 140-100 = 40 unit of work remained.
40/140 =2/7.
B takes 20 days.
Total work = LCM = 140,
A+B =20 unit/day.
For 5 days =100 unit work is done.
Therefore, 140-100 = 40 unit of work remained.
40/140 =2/7.
(1)
Bineeta said:
8 years ago
Why not E?
We required statement II also for solving the equation. Please explain me.
We required statement II also for solving the equation. Please explain me.
(1)
Nikhitha said:
8 years ago
@Manju.
Firstly given, x/15+5/10=1.
Where we get x/15=1-1/2.
On LCM we get, x/15=1/2.
Now, Cross multiply, 2x=15; x=15/2.
Firstly given, x/15+5/10=1.
Where we get x/15=1-1/2.
On LCM we get, x/15=1/2.
Now, Cross multiply, 2x=15; x=15/2.
Manju p said:
8 years ago
How to find "x "when ((x÷15)+(5÷10))=1 is given.
Please tell me.
Please tell me.
VISITHRA. S said:
8 years ago
How "Remaining work =1-5" is done? Not understood please explain.
(1)
Nabanita Biswas said:
8 years ago
From where we get 5?
Vitthal jadhav said:
9 years ago
B's 1 day's work = 1/20.
(A+ B)'s 1 day's work = 1/7.
=> (A + B)'s 5 day's work = 5/7.
Remaining work = 1 - 5 = 2.7 7
2/7work was carried by A.
(A+ B)'s 1 day's work = 1/7.
=> (A + B)'s 5 day's work = 5/7.
Remaining work = 1 - 5 = 2.7 7
2/7work was carried by A.
Sunilkumar said:
9 years ago
@Pihu.
A + B's 1day work = 1/7day.
B's 1day work = 1/20 day.
Then,
A + 1/20 = 1/7
After that,
A = 1/7 - 1/20.
by cross multiply,
A = 20 - 7\20 * 7.
A = 13\140.
Then we taking the I in that A completed the job alone after a&b worked together for 5 days.
So, 1st we take a can complete by 5 days.
Then A's 5days work = 13 * 5/140.
then we get 13/28.
Now we want to find A + B's 5days work.
A + B's 1day work = 1/7 day.
Then A + B's 5days work = 5/7 days.
Remaining work = 1 - 5/7 = 2/7 days.
Total part of work by A = 2/7 + 13/28
By taking Lcm = 2 * 4/7 * 4.
Then,
= 8/28 + 13/28 = 8 + 13/28.
After simplification we get,
= 21/28 = 3/4.
A + B's 1day work = 1/7day.
B's 1day work = 1/20 day.
Then,
A + 1/20 = 1/7
After that,
A = 1/7 - 1/20.
by cross multiply,
A = 20 - 7\20 * 7.
A = 13\140.
Then we taking the I in that A completed the job alone after a&b worked together for 5 days.
So, 1st we take a can complete by 5 days.
Then A's 5days work = 13 * 5/140.
then we get 13/28.
Now we want to find A + B's 5days work.
A + B's 1day work = 1/7 day.
Then A + B's 5days work = 5/7 days.
Remaining work = 1 - 5/7 = 2/7 days.
Total part of work by A = 2/7 + 13/28
By taking Lcm = 2 * 4/7 * 4.
Then,
= 8/28 + 13/28 = 8 + 13/28.
After simplification we get,
= 21/28 = 3/4.
(3)
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