A family buys $2\frac{2}{5}$m and $5\frac{7}{5}$m of cloth for two dresses. If each of them costs $\mathrm{Rs}. 20$ per meter, then what will be the total cost? 

 

 

Given:

Cloth bought for first dress $=2\frac{2}{5} \mathrm{m}$

Cloth bought for second dress $=5\frac{7}{5} \mathrm{m}$

Cost of cloth per meter $=\mathrm{Rs}. 20$ per meter

First we will convert mixed fraction to improper fraction, so

$2\frac{2}{5}=\frac{\left(5\times 2\right)+2}{5}=\frac{12}{5}$

$5\frac{7}{5}=\frac{\left(5\times 5\right)+7}{5}=\frac{32}{5 }$

Now, cost of $\frac{12}{5} \mathrm{m}$ cloth $=\frac{12}{5}\times 20=\mathrm{Rs}. 48$

and cost of $\frac{32}{5} \mathrm{m}$ cloth  $=\frac{32}{5}\times 20=\mathrm{Rs}. 128$

Therefore, total cost $=128+48=\mathrm{Rs}. 176$

Hence, option D is correct.