Question

The length,breadtg,height of room are 5m,4m,3m, respectively.find the cost of waahimh the wall of the room and the celling at the rate of 7.5 per m2.

Answer 1

Washing /painting is only needed on the sides and on the ceiling.
So the area to be painted = 2*b*h + 2*h*l + l*b
= 2*4*5 +2*3*5+5*4
=90 m2
Net cost to spend = 90 m2 *7.5/m2
= Rs 675

Answer 2

Answer:

length 5m

Breadth 4m

Height 3m

curved surface area + area of rectangle is used here....

2(l+b)h +lb

2( 5+4)×3 +4×5 m²

= 74m²

Cost of white washing = RS. 7.50

7.50×74=Rs.555