Q. A and B together can do a piece of work in 5 days and A alone can do it in 8 days, then B alone can do the same piece of work in :
Answer: $latex 13\tfrac{1}{3}days&s=1$
Notes: (A + B)'s 1 day's work $latex =\frac{1}{5}&s=1$ A's 1 day's work $latex =\frac{1}{8}&s=1$ ∴ B's 1 day's work $latex =\frac{1}{5}-\frac{1}{8}=\frac{8-5}{40}=\frac{3}{40}&s=1$ ∴ B alone will complete the work in $latex \frac{40}{3}=13\tfrac{1}{3}\ days&s=1$. Hence option [B] is correct answer.<

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