Question

the floor of a rectangular hall has a perimeter of 280cm ,its height is 6m. find the cost of white washing the four wall at the rate of rs.10per m 2​

Answer 1

Answer

The floor is in rectanguar shape.

Perimeter of the rectangular hall=2(l+b)=280m

⇒l+b=

2

280

=140m

Height of the wall=h=6m

White washing the four walls including the doors and windows

=Lateral surface area of a cuboid

=2(bh+lh)=2h(l+b)

=2×6×140m

2

=1,680‬m

2

Cost for White washing 1m

2

=Rs.10

Cost for White washing 1,680‬m

2

=Rs.10×1,680‬m

2

=Rs16,800‬