Question

The dimensions of a room are $12m\times 7m\times 5m$. Find

(a) The diagonal of the room

(b) The cost of flooring at the rate of Rs. 2 per m sq.

(c) The cost of whitewashing the room excluding the floor at the rate of Rs. 3 per m sq.

Answer 1

(a) The diagonal of the room = $\sqrt{l^2+b^2+h^2}=\sqrt{{12}^2+7^2+5^2}=\sqrt{218}$ $m$

(b) Base area = $lb=12\times 7=84$ $m^2$

Therefore, cost of flooring = $84\times 2=Rs.168$

(c) The total area to be whitewashed

= LSA + Area of roof

$=2(l+b)h+lb$

$=2(12+7)5=274$ $m^2$

Therefore, cost of whitewashing = $274\times 3=Rs.822$