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A cube-shaped box has a side length of 15 inches and contains 27 identical cube-shaped blocks. What is the surface area of all 27 blocks compared to the surface area of the box?The side length of the blocks is ____ inches, so the total surface area of the 27 blocks is ____ square inches. This is ____ the surface area of the box.

User Zaheer Ansari
by
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1 Answer

22 votes
22 votes

Answer:

The side length of the blocks is 5 inches

the total surface area of the 27 blocks = 27 x 150 = 4050 square inches

This is 3 times the surface area of the box.

Step-by-step explanation:

From the information given,

the cube shaped box with side length of 15 inches contains 27 identical cube-shaped blocks. Recall, the length of each side of a cube is equal. We would calculate the volume of the cube shaped box. The formula for calculating the volume of a cube is

Volume = s^3

Volume of cube shaped box = 15^3 = 3375

Thus,

Volume of 27 identical cube-shaped blocks = 3375

Volume of one identical cube-shaped block = 3375/27 = 125 in^2

We would find the side length of one identical cube-shaped block

Thus,

125 = s^3

Taking the cube root of both sides,

s = cube root of 125

s = 5

The side length of the blocks is 5 inches

The formula for calculating the surface area of a cube is expressed as

surface area = 6a^2

Surface area of larger cube = 6 x 15^2 = 1350

surface area of each small block = 6 x 5^2 = 150

the total surface area of the 27 blocks = 27 x 150 = 4050 square inches

Ratio of surface area of the 27 blocks to the original box = 4050/1350 = 3

This is 3 times the surface area of the box.



User Mutu Yolbulan
by
2.5k points
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