Question

A hall is 15 m long and 12 m broad. If the sum of the areas of the floor and the ceiling is equal to the sum of the areas of four walls, the volume of the hall is:

Answer 1

lenght= 15m
breadth= 12m
area of ceiling and floor 2*2(l+b)
2*2(15+12)=108m

Given that area of floor and ceiling is equal to area of 4 walls
Hence area of four walls= 108m
2h(l+b)=108
2h(15+12)=108
54h=108
h=108/54=2m
Now volume = l*b*h
15*12*2=360 metre cube

So volume of hall is 360 meter cube 

Answer 2

2[15+12]*h=2{12*15}
h=180/27 m =20/3 m
v=[15*12]20/3 
v=1200m3