# Aptitude - Volume and Surface Area - Discussion

Discussion Forum : Volume and Surface Area - General Questions (Q.No. 3)
3.
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:
720
900
1200
1800
Explanation:

2(15 + 12) x h = 2(15 x 12)

 h = 180 m = 20 m. 27 3

 Volume = 15 x 12 x 20 m3 = 1200 m3. 3

Video Explanation: https://youtu.be/V8EQ1YIaH74

Discussion:
74 comments Page 1 of 8.

I can not understand the meaning of cube in answer.

Here given that

Area of four walls = (area of the base )+(area of ceiling)

As per Surface area of a cuboid we have 2(l+b)*h
Area of base is (l*b)

So from these 2 formula e we get the equation explained in the answer section

What is ceiling?

@ akansha ceiling means top wall, and hence its area is always equal to floor.

Ajith kumar said:   1 decade ago
Well not exactly. A ceiling is an overhead interior surface of a room that conceals the underside of the floor or roof structure above.

Hello all,

I could not understand the first step of the explanation.

According to this site surface area of cuboid is 2 (lb + bh + lh) sq. units.

Hello, can any one clearly explain the basics of the concept please ?

Hey can any one explain how you got 180/27cm ?