# Aptitude - Time and Work - Discussion

### 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.

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.

 [A]. I alone sufficient while II alone not sufficient to answer [B]. II alone sufficient while I alone not sufficient to answer [C]. Either I or II alone sufficient to answer [D]. Both I and II are not sufficient to answer [E]. Both I and II are necessary to answer

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).

 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 and 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: B=20 When we substitute B's Value we will get A's Value. A+20=7 A=(13). 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) @Ankush. 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) @Ankush. Agree with you, even I got the same answer.

 Pihu said: (Aug 2, 2016) @Ankush. How you got 28? please explain.

 Sunilkumar said: (Sep 19, 2016) @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.

 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) @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.

 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. 40/140 =2/7.

 Keshri said: (Jul 22, 2020) It's easily understandable; A+B=7. B=20. After substituting A's efficiency is 13. So, 1 is agreed.