Question

A class room is 7m long, 6.5m wide and 4m high. It has one 3m×1.4m and three windows each measuring 2m×1m. The interior of the wall is to be white washed. Find the cost of white washing at the rate of Rs 3.50 per m

Answer 1

Area of four walls=(2h(l+b))
=(2x4(7+6.5))
=(8x13. 5)
=108m square
area of one window =3mx1. 4m
=4.2m square
area of three window =3(2mx1m)
=6m square
total area of windows =(4.2+6)m square
=10.2m square
Area for whitewashing =(108-10.2)m square
=97.8m square
cost of 1 m square white washing = 3.50rupee
cost of 97.8m square white washing=3.50x97.8
=342.3 rupees


I hope this solution is helpful for u

Answer 2

Dimensions of the room: length-7m, width-6.5m, height-4m.

Area of four walls=[2h(l+b)]

=[2x4(7+6.5)]

=(8x13. 5)

=108m sq.

area of one window =3mx1. 42

=4.2m sq.

area of three windows =3(2mx1m)

=6m sq.

total area of windows =(4.2+6)m sq.

=10.2m sq.

Area for whitewashing =(108-10.2)m sq.

=97.8m sq.

cost of 1 m sq. white washing = 3.50rupee

cost of 97.8m sq. white washing=3.50x 97.8 =342.3 rupees