# Aptitude - Volume and Surface Area - Discussion

Discussion Forum : Volume and Surface Area - General Questions (Q.No. 15)
15.
How many bricks, each measuring 25 cm x 11.25 cm x 6 cm, will be needed to build a wall of 8 m x 6 m x 22.5 cm?
5600
6000
6400
7200
Explanation:

 Number of bricks = Volume of the wall = 800 x 600 x 22.5 = 6400. Volume of 1 brick 25 x 11.25 x 6

Discussion:
11 comments Page 1 of 2.

Please tell me, how to calculate the volume of the hollow cuboid.

How can we divide it simply as both wall and brick is given with different calibrations.
(1)

Faraz hasan said:   1 decade ago
No.of bricks = volume of wall / bricks volume.

First we convert meter into cm.

1mtr = 100cm.
i.e 8*100= 800cm.
6*100= 600cm.

Now apply value according to formula,

800*600*22.5 / 25 *11.25*6 = 6400.

Ramesh said:   8 years ago
Then why this formula is not given in the list.

Ranjitha S said:   8 years ago

Hrushi said:   7 years ago
First, we calculate the volume of brick.

Then, we calculate volume of wall.

Then we think.

How many bricks are required to constract the given volume of wall?
So,
1volume of brick * X = volume of the wall.
(Here X =number of bricks).
Then X = volume of wall/volume of brick.

Srj said:   7 years ago
Why volume?

D Priya said:   7 years ago
Hi @Srj,

Both the wall and brick are in cuboid shape. So we consider the total volume of wall to fill with the total volume of bricks. No doubt shud arise to use TSA of cuboid because TSA talks only about the area. But we fill the wall with bricks so we calculated using volume.

Tharanikaran said:   5 years ago
This is correct. But, Please consider the cement motor.

Raju said:   5 years ago
A solid rectangular block of dimensions 6.6m 3.25m 1.25m is recast into a hollow cylindrical pipe of internal diameter 60cm and thickness 5cm the length of the pipe in meters is?
(1)