Discussion :: Time and Work - Data Sufficiency 1 (Q.No.1)
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.
|Ankush said: (Jul 20, 2010)|
|In this ques no doubt option A is correct, but I guess the explanation given is correct only if it's asked to find out part of work done by A alone.
But ques is wht part of work ws carried out by A(alone + A's contribution when both A & B worked together)which can be calculated as
B's 1 day's work = 1/20
(A+ B)'s 1 day's work = 1/7
=> A's 1 day's work = 1/7 - 1/20 = 13/140
=> A's 5 day's work = 13/28
Now , (A + B)'s 5 day's work = 5/7
Remaining work = 1 - 5/7 = 2/7
=> 2/7 work was carried by A alone
Total part of work carried by A = 2/7+13/28= 3/4.
|Singh said: (Nov 1, 2010)|
|Ankush you are genious yaar. You are 100% correct.|
|Deepa said: (Oct 27, 2011)|
|Why we have calculated only for 5 days it may be 6 days too. ?|
|Javeed Ahmed Khan said: (Dec 16, 2011)|
|Easy way of solving this question is:
A and B together can complete a task in 7 days which means
A+B = 7
B alone can do it in 20 days:
When we substitute B's Value we will get A's Value.
1st statement says that A will complete the task 5 days after A & B worked together, which is acceptable statement.
|Munna said: (Dec 27, 2011)|
|How we get 5/7 and 1-5/7=2/7 how it is possible tell me friend?|
|Lakshminarayana said: (Feb 23, 2016)|
|Please explain deep I can't understand.|
|Srikanth said: (Mar 19, 2016)|
|Could someone help me, how shall we get that 2/7 value.
2/7+1/7 results : 21/49 or 3/7 ?
|Tunna said: (Jun 1, 2016)|
Can you explain how you got the remaining work = 1 - 5/7 = 2/7 & A's 5days work= 13/28? How you got 28?
|Akshay said: (Jun 20, 2016)|
Agree with you, even I got the same answer.
|Pihu said: (Aug 2, 2016)|
How you got 28? please explain.
|Sunilkumar said: (Sep 19, 2016)|
A + B's 1day work = 1/7day.
B's 1day work = 1/20 day.
A + 1/20 = 1/7
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.
= 8/28 + 13/28 = 8 + 13/28.
After simplification we get,
= 21/28 = 3/4.
|Vitthal Jadhav said: (Feb 12, 2017)|
|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.
|Nabanita Biswas said: (Jun 29, 2017)|
|From where we get 5?|
|Visithra. S said: (Jul 28, 2017)|
|How "Remaining work =1-5" is done? Not understood please explain.|
|Manju P said: (Aug 10, 2017)|
|How to find "x "when ((x÷15)+(5÷10))=1 is given.
Please tell me.
|Nikhitha said: (Aug 19, 2017)|
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.
|Bineeta said: (Dec 28, 2017)|
|Why not E?
We required statement II also for solving the equation. Please explain me.
|Shubham Nale said: (Jul 9, 2020)|
|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.
|Keshri said: (Jul 22, 2020)|
|It's easily understandable;
After substituting A's efficiency is 13.
So, 1 is agreed.
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