How Much Time will be Taken by B?

A can do a piece of work in 10 days and B can do it in 20 days. They start the work together. But after 5 days, A leaves off. B will do the remaining work in

  1. 5 days
  2. 6 days
  3. 8 days
  4. 10 days
Monis Rasool Professor Asked on 12th September 2015 in Maths.
Add Comment
  • 1 Answer(s)

    Answer: (1) 5 days

    Explanation:-
    A can do a piece of work = 10 days
    Therefore, A can a piece of work in a day = 1/10

    B can do the same work = 20 days
    Therefore, B can the same work in day = 1/20

    Then, A and B can together in a day = 1/10 + 1/20
    = (2 + 1) /20
    = 3/20

    A and B can together work in 5 days = 5 x 3 /20
    = 15/20
    Then, the remaining work = 1 – 15/20
    = (20 – 15)/20
    = 5/20
    = 1/4
    Then, B can the remaining work = 20/4 = 5 days

    Hence, the answer is (1) 5 days.

    Anurag Mishra Professor Answered on 13th September 2015.
    Add Comment
  • Your Answer

    By posting your answer, you agree to the privacy policy and terms of service.