RRB NTPC 18 January 2017 Paper

(1)Let a man and a woman can do work in x and 2x days respectively.According to the question,
$10\mathit{x}+52\mathit{x}=\frac{1}{60}$ $\Rightarrow \frac{25}{2\mathit{x}}=\frac{1}{60}$
$\Rightarrow \mathit{x}=30\times 25=750$ days
$\Rightarrow 2\mathit{x}-1500$ days
Now, 5 men and 20 women will do the work in
$\frac{5}{\mathit{M}}+\frac{20}{\mathit{w}}=\frac{5}{750}+\frac{20}{1500}$ $=\frac{30}{1500}=150$
So, they will do the whole work in50 days and half of the work in 25days.