the dimensions of a room are 9m,8m,6.5m.it has 1 door of dimensions 2m,1.5m and two windows of each of dimensions 1.5m,1m.find cost of whitewashing the walls at Rs.6.40 per m sq.nplzzz answr meh fst..xammz on strdy...
Length of a door = 2m
Breadth of the door = 1.5m
∴ Area of one door = lb = 2×1.5=3m 2
Length of the window = 1.5m
Breadth of the window = 1m
Area of the window = lb= 1.5×1 = 1.5m 2
∴ Area of two windows = 2×1.5 = 3m 2
Area of the doors + Area of the windows = 3m 2 + 3m 2 = 6m 2
Length of the wall = 9m
Breadth of the wall = 8m
Height of the wall = 6.5m
Area of the wall = LSA of a cuboid = 2h(l+b)
= 2×6.5 (9+8)
= 13×17
=221m 2
Required area of the wall to be painted = Area of the wall - Area of the doors and windows
i.e., area of the wall to be painted=(221-6)=215m 2
area of the wall to be painted = 215m 2
Cost of painting 1m 2 of the wall = Rs. 6.40
Cost of painting 215m 2 of the wall = Rs. (6.40×215)
Cost of painting the wall = Rs. 1376