Question

Find the cost of painting the four walls and the ceiling of the room having the dimensions
2.5 m × 1.3 m x 2.2 m at the rate of 9 per m2.​

Answer 1

Given,
Length,L =2.5 m
Breadth,B = 1.3 m
Height,H = 2.2m
Cost of painting = ₹9 per m2

Solution,
Area of four walls = CSA of cuboid = 2*(L+B)*H
= 2* (2.5+1.3)*2.2
= 2*3.8* 2.2
= 16.75 m^2
Area of ceiling = area of rectangle =L*B
=2.5*1.3
= 3.25 m^2
Area to paint= area of four walls+ area of ceiling
= 16.75+ 3.25
=20 m^2
Cost of painting 1m^2 = ₹9 per m2
Cost of painting 20m^2 = 20 * 9
= ₹180