Question

The cost of polishing $35$ identical wooden cubical boxes at the rate of $20$ rs. per cm${}^2$ is $1,51,200$ rs. find the edge of each cubical box.

Answer 1

Cost of painting $1$ cube = $\frac{151200}{35}=4320$ $Rs.$

Surface area of $1$ cube = $\frac{4320}{20}=216$ $c{m}^2$

Therefore,

$6a^2=216$

$a^2=36$

$a=6$

So, side of cubical box = $6$ $cm$.