CMAT 2020 Solved Question Paper

The work done by
Man : Woman : Child = 3 : 2 : 1
∴ $15\mathit{M}+21\mathit{W}+30\mathit{C}$ $=15\times 3\mathit{C}+21\times 2\mathit{C}+30\mathit{C}$
$=45\mathit{C}+42\mathit{C}+30\mathit{C}$
$=117\mathit{C}$
And, $20\mathit{M}+30\mathit{W}+36\mathit{C}$ $=20\times 3\mathit{C}+30\times 2\mathit{C}+36\mathit{C}$
$=60\mathit{C}+60\mathit{C}+36\mathit{C}$
$=156\mathit{C}$
It is given that,
(20 men + 30 women + 36 children)
= 156 children earn ₹ 78 per day
∴ 1 child earn $\mathrm{₹}\frac{78}{156}$ per day $=\mathrm{₹}\frac{1}{2}$
∴ 15 men + 21 women + 30 children = 117 children
∴ 117 children earn ₹ $\frac{1}{3}\times 117$ per day
i.e., $\left(\frac{1}{2}\times 117\times 18\times 7\right)$ earn in 18 weeks $=\mathrm{₹}7371$