Question

What's the cost of painting a box which is in the shape of a cuboid of dimensions $3m\times 4m\times 5m$ at a rate of $₹5/m^2$?

• A. $₹300$
• B. $₹470$
• C. $₹1500$
• D. $₹900$

Answer 1

The correct option is B $₹470$

We know that,
Surface area of cuboid
$=2(lb+bh+lh)$

Given that,
dimension of the box
$=3m\times 4m\times 5m$
cost of painting
$=₹5/m^2$

Now,
Surface area of box
$=2(3\times 4+4\times 5+5\times 3)$
$=94m^2$

Cost of painting
$=\text{Surface area of box}\times \text{Cost of painting per m^2 area}$
$=94\times 5$
$=₹470$