Question

A room is 9 m by 8 m by 6.5 m. It has one door or dimensions $(2m\times 1.5m)$ and four windows each of dimension $(1.5m\times 1m)$. Find the cost of painting the walls at Rs. 50 per $m^2$

Answer 1

Given dimension of room $=9m\times 8m\times 6.5m$

now CSA of room =2(lh+bh)

=2h[l+b]

CSA of room $=2\times 6.5[9+8]=13\times 17$

CSA of room $=221m^2....\left(1\right)$

now

area of door $=2\times 1.5=3m^2$

area of 4 window =4x(1.5,1)=6 m^{2}$

area to be painted =CSA of room -(arof door)-(ar of window)

area to be painted $=221-6-3=212m^2$

cost of painting = area x 50 $=212\times 50Rs$

cost of painting =10,600 Rs.