Question

Question 2
The length, breadth and height of a room are 5 m, 4 m and 3 m respectively. Find the cost of whitewashing the walls of the room and ceiling at the rate of $Rs7.50per{m}^2$.

Answer 1

It is given that,
Length (l) of room = 5 m
Breadth (b) of room = 4 m
Height (h) of room = 3 m
It can be observed that four walls and the ceiling of the room are to be whitewashed. The floor of the room is not to be whitewashed.
Area to be whitewashed = Area of walls + Area of ceiling of the room
= 2lh + 2bh + lb
$=[2\times 5\times 3+2\times 4\times 3+5\times 4]m^2=(30+24+20)m^2=74m^2$
Cost of whitewashing per $m^2$ area = Rs. 7.50
Cost of whitewashing $74m^{2}area=Rs.(74\times 7.50)=Rs.555$