Time and Work - Quantitative Aptitude (MCQ) questions for Q. 134

Q.  A can build a wall in the same time in which B and C together can do it. If A and B together could do it in 25 days and C alone in 35 days, in what time could B alone do it?
- Published on 15 Jun 15

a. 175 days
b. 100 days
c. 90 days
d. None of these

ANSWER: 175 days

Related Content

 

    Discussion

  • Shweta   -Posted on 06 Jan 21
    Given:
    A can build a wall at the same time in which B and C together can do it.
    A = B + C --- (1)
    If A and B together could do it in 25 days and C alone in 35 days.
    A+B 1 day work = 1/25 -- (2)
    C 1-day work = 1/35 ---(3)
    Substitute the value of A from equation (1) to equation (2).
    B+C +B = 1/25
    B's 1-day work = (1/25 - 1/35) 1/2
    LCM of 25 and 35 is 175, after solving this we get
    B's 1-day work = 1 / 175
    So, B alone does work in 175 days.
  • Pooja   -Posted on 14 Feb 17
    given : (1/A)=(1/B)+(1/C) -------> 1
    (1/A)+(1/B)= 1/25 -------> 2
    (1/C)=(1/35) -------> 3
    (1)-(2)
    -(1/B) = (1/B)+(1/C)-(1/25)
    re-arranging above equation
    (1/25)=(2/B)+(1/C)
    From (3)
    (1/25)=(2/B)+(1/35)
    Simplifying above equation
    (1/25)-(1/35)=(2/B)
    (1/B)=(1/175)
    B=175 days

➨ Post your comment / Share knowledge


Enter the code shown above:

(Note: If you cannot read the numbers in the above image, reload the page to generate a new one.)
▲