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A cylinder has a height of 15 inches. A similar cylinder has a height of 20 inches.

What is the ratio of the surface area of the larger cylinder to the surface area of the smaller cylinder?

User Iammrmehul
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2 Answers

6 votes

Answer:

16:9

Explanation:

I took the test

User Johnny Oshika
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3 votes

The surface area of a cylinder can be calculated using the formula:

Surface area = 2πr² + 2πrh

where r is the radius of the base and h is the height of the cylinder.

Let's assume that the radius of the base of the smaller cylinder is r, then the radius of the base of the larger cylinder is 4/3 r, since the height is increased by 5 inches or 1/3 of the original height.

So, the surface area of the smaller cylinder is:

Surface area = 2πr² + 2πrh

And the surface area of the larger cylinder is:

Surface area = 2π(4/3 r)² + 2π(4/3 r)(15)

Simplifying these expressions, we get:

Surface area of smaller cylinder = 2πr² + 30πr

Surface area of larger cylinder = 2π(16/9 r²) + 40πr

Now we can find the ratio of the surface area of the larger cylinder to the surface area of the smaller cylinder:

Ratio = Surface area of larger cylinder / Surface area of smaller cylinder

= (2π(16/9 r²) + 40πr) / (2πr² + 30πr)

Simplifying this expression, we get:

Ratio = (32/9 r + 40) / (2r + 30)

= (32/9 r + 40) / 2(r + 15)

Since the cylinders are similar, the ratio of their surface areas is proportional to the square of the ratio of their heights:

Ratio = (20/15)²

= 1.7778

So the ratio of the surface area of the larger cylinder to the surface area of the smaller cylinder is approximately 1.7778, or 1.78 to two decimal places.

User Ridoy
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