Question

A rectangular room of length 10m breadth 6m and height 3m. The four walls and the roof have to be painted.if the cost of painting is Rs. 75 per square meter,what is the total cost ? The area of the windows and door is 6 sq.m, which will not be painted.

Answer 1

cost of painting=[(csa of rectangle+area of roof)-area of window]*cost of painting
                       ={[2(l+b)h+l*b*h]-6}*75
                         ={[2(10+6)3+180]-6}*75
                           =[276-6]*75
                             =270*75
                               =Rs.24300

Answer 2

Area of the whole room (with windows and doors)
L x B x H
10 x 6 x 3
60 x 3
180sq m.

Area of windows and doors = 6 sq m

Area of room to be painted = 180-6
                                                =174
1 sq m = Rs.75
174 sq m =75 x 174
                  =13050
 
Ans : Rs. 13050