Question

A rectangular room is 8m long,5m wide and 3.5m high .It has 2 doors of size1.2m by 2m and 2 windows of size 1.4m by 1.2m.Find the cost of whitewashing the walls and the ceiling of the room at the rate of Rs 5 per square meter.​

Answer 1

Answer:

dimensions of room =8+5+3.5

Area of window=2×1.5

then, area of 2 window=2×2×1.5=6m*3

area of 2 door=1.4×1.2×2

= 16.2m*3

(In this it is asked about 4 wall and the celling also so we need to put this formula)

area of 4 walls +area of celling -area of door and window

area of 4 wall=2(l+b) h

=2(8+5) ×3.5

=2×13×3.5

=26×3.5

=91

area of ceiling=l×b

=8×5

=40

area of both door and window=6m*3+16.2m*3

= 22.2

91+40-22.2=108.8m

cost of whitewashing the wall=108.8×5=544₹