BA LLB Banaras Hindu University 2019 Solved Paper

From the given information,
One day work of 4 men and 6 women $=\frac{1}{8}$
$4\mathit{M}+6\mathit{W}=\frac{1}{8}$
⇒ \;\;
......(i)
One day work of 3 men and 7 women $3\mathit{M}+7\mathit{W}=\frac{1}{10}$
$\Rightarrow 10\left(3\mathit{M}+7\mathit{W}\right)=1$
$30\mathit{M}+70\mathit{W}=1$.....(ii)
From Eqs. (i) and (ii), we get
$32\mathit{M}+48\mathit{W}=30\mathit{M}+70\mathit{W}$
$2\mathit{M}=22\mathit{W}$
$\mathit{M}=11\mathit{W}$
Put value in Eq. (i)
$32\left(11\mathit{W}\right)+48\mathit{W}=1$
$352\mathit{W}+48\mathit{W}=1$
$\mathit{W}=\frac{1}{400}$
1 woman completes the work in 400 days
Now, 10 women completes the work in
$=\frac{10}{400}=\frac{1}{40}$
$=40$ days