Question

The cost of papering the four walls of a room $12m$ long at Rs.$6.50$ per square metre is Rs.$1638$ and the cost of matting the floor at Rs.$3.50$ per square metre is Rs.$378$. Find the height of the room.

Answer 1

length of room $\left(l\right)=12m$

area of floor $=l\times b=12\times b$

Total cost of matting floor $=12\times b\times 3.50=378$

$42b=378$

$b=9m$

Area of walls of the room $=2h(l+b)$

$=2h(12+9)$

$=42h{m}^2$

Total cost of papering walk $=42h\times 6.50=1638$

$273h=1638$

$h=6m$.