A and B together can do a piece of work in 8 days, while B alone can f

1.	A and B together can do a piece of work in 8 days, while B alone can finish it in 12 days. In how many days can A alone finish the work?
Answer» A alone can complete a work in 12 days. A and B together can complete it in 8 days. How long will B alone take to complete the work? [A]20 days [B]24 days [C]16 days [D]18 days 24 days A’s one DAY’s work = \FRAC{1}{12} (A + B)’s one day’s work = \frac{1}{8} ∴ B’s one day’s work = = \frac{1}{8} - \frac{1}{12} = \frac{3-2}{24} = \frac{1}{24} ∴ B alone can do the work in 24 days. Hence option [B] is the RIGHT answer.

A and B together can do a piece of work in 8 days, while B alone can finish it in 12 days. In how many days can A alone finish the work?

Answer»

A alone can complete a work in 12 days. A and B together can complete it in 8 days. How long will B alone take to complete the work?

[A]20 days

[B]24 days

[C]16 days

[D]18 days

24 days

A’s one DAY’s work = \FRAC{1}{12}

(A + B)’s one day’s work = \frac{1}{8}

∴ B’s one day’s work =

= \frac{1}{8} - \frac{1}{12} = \frac{3-2}{24} = \frac{1}{24}

∴ B alone can do the work in 24 days.

Hence option [B] is the RIGHT answer.