A can do a piece of work in 10 days, while A and B together can complete it in $2\frac{1}{2}$days. How long will B alone take to complete the work?

$\frac{10}{3}$

A = 10 days,

A + B = \( { 2}_{ 2}^{ 1} \) days,

⇒ Efficiency = A +B = 4, A =1

Simplifying, we get, Efficiency of B = 3.

⇒ Time taken by B to complete the work alone = \(\frac{10}{3}\) days    ..(\(\frac{Work}{Efficiency}\) = Time )