AP ICET 2016 Paper

60% work ≡ 15 days
∴ 100% work $\equiv 15\times \frac{100}{60}=25$days
⇒ A alone can do the work in 25 days
Remaining work = 40% $=\frac{2}{5}$
Let B alone do the work in x days.
Aliter
Remaining 40 % work is done by A + B in 5 days
∴ A + B will do 60% work in $5\times \frac{60}{40}=\frac{15}{2}$
A alone does 60% work in 15 days
⇒ A and B are equally efficient
∴ Time taken by B or A alone to do 100% work $=15\times \frac{100}{60.}=25$days