The solid brick shown is made of small bricks of side 1...

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The solid brick shown is made of small bricks of side 1. When the large brick is disassembled into its component small bricks, the total surface area of all the small bricks is how much greater than the surface area of the large brick?

A. 32
B. 40
C. 60
D. 72
E. 80

The OA is B.

I solved this PS question as follows,

From the figure we can see: The large brick is made up of 12 cubes.
Length of the large brick = 3.
Width of large brick = 2.
Height of large brick = 2.

Total Surface area of the large brick = Total Surface area of a Cuboid = 2(3 * 2 + 2 * 2 + 3 * 2) = 2 * 16 = 32.

Total Surface area of all 12 smaller bricks = 12 * (6 * 1) = 72 .

TSA of all small bricks - TSA of large brick = 72 - 32 = 40.

Has anyone another approach to solve this PS question? Regards!
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by Jay@ManhattanReview » Sun Apr 08, 2018 10:51 pm
AAPL wrote:Image

The solid brick shown is made of small bricks of side 1. When the large brick is disassembled into its component small bricks, the total surface area of all the small bricks is how much greater than the surface area of the large brick?

A. 32
B. 40
C. 60
D. 72
E. 80

The OA is B.

I solved this PS question as follows,

From the figure we can see: The large brick is made up of 12 cubes.
Length of the large brick = 3.
Width of large brick = 2.
Height of large brick = 2.

Total Surface area of the large brick = Total Surface area of a Cuboid = 2(3 * 2 + 2 * 2 + 3 * 2) = 2 * 16 = 32.

Total Surface area of all 12 smaller bricks = 12 * (6 * 1) = 72 .

TSA of all small bricks - TSA of large brick = 72 - 32 = 40.

Has anyone another approach to solve this PS question? Regards!
This is perfect. :)

-Jay
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by Scott@TargetTestPrep » Wed Apr 11, 2018 5:47 am
AAPL wrote:Image

The solid brick shown is made of small bricks of side 1. When the large brick is disassembled into its component small bricks, the total surface area of all the small bricks is how much greater than the surface area of the large brick?

A. 32
B. 40
C. 60
D. 72
E. 80
The surface area of the large brick is composed of :

2(3 x 2) + 2(2 x 2) + 2(3 x 2) = 12 + 8 + 12 = 32

When the large brick is disassembled into small bricks of side 1, it can be disassembled into 3 x 2 x 2 = 12 small bricks. Since the surface area of each small brick is 6 x 1^2 = 6, the total surface area of the 12 small bricks is 6 x 12 = 72. Thus the total surface area of all the small bricks is 72 - 32 = 40 greater than the surface area of the large brick.

Answer: B

Scott Woodbury-Stewart
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