Question

The cost of constructing a wall 8 m long, 4 m high and 20 cm thick at the rate of Rs 25 per $m^3$ is

• A. Rs. 16
• B. Rs. 80
• C. Rs. 160
• D. Rs. 320

Answer 1

The correct option is C

Rs. 160

$\text{Length of wall (l)}=8m$

$\text{Breadth (b)}=20cm=\frac{1}{5}m$

$\text{Height (h)}=4m$

$\therefore \text{Volume of wall}=lbh=8\times \frac{1}{5}\times 4m^3$$=\frac{32}{5}{m}^3$

$\text{Rate of constructing the wall}$ $=Rs25per{m}^3$

$\therefore \text{Total cost}=Rs\frac{32}{5}\times 25=Rs160$