Question

Find the quantity of paint required to paint all the faces of a room of dimensions 10 m $\times$ 8 m $\times$ 10 m, assuming paint to have negligible thickness.

• A. 360$m^2$
• B. 520$m^2$
• C. 800$m^2$
• D. 420 $m^2$

Answer 1

The correct option is B

520$m^2$

Length (l) = 10 m
Breadth (b) = 8 m
​Height (h) = 10 m
It is given that all the faces have to be painted and the paint is assumed to have negligible thickness.
Hence, we have to use the formula for total surface area of a cuboid.
Amount of paint required
$=2(l\times b+b\times h+l\times h)=2(10\times 8+8\times 10+10\times 10)=2(80+80+100)=520m^2$