A cylinder flower pot with open top needs to be painted. The height is 9 inches and radius is 3 inches. If it takes Troy 5 minutes to paint 40 square inches, how long to the minute will it take him to paint the outside of the flower pot.

Surface Area = (pi * r^2) + (pi * r * h)

3.14 * 9 = 28.26 sq. in
3.14 * 4 * 9 = 113.04 sq. in.

113.04 + 28.26 = 141.3 total sq. in.

40/5 = 8 sq. in. per minute

Divide the total square inches by 8 to find the time.

The answer in the book is 25 minutes but with your figures I came up with 17.66 rounded to 18 minutes?

To find out how long it will take Troy to paint the outside of the flower pot, we need to calculate the surface area of the cylinder. The surface area of a cylinder can be calculated using the formula:

Surface Area = 2πrh + 2πr²

Where:
- π is a mathematical constant approximately equal to 3.14159
- r is the radius of the cylinder's base
- h is the height of the cylinder

In this case, the height (h) of the cylinder is given as 9 inches, and the radius (r) is given as 3 inches.

Let's calculate the surface area of the cylinder:

Surface Area = 2πrh + 2πr²
Surface Area = (2 * 3.14159 * 3 * 9) + (2 * 3.14159 * 3²)
Surface Area = 169.64604 + 56.54867
Surface Area ≈ 226.19471 square inches

Now, we know that Troy can paint 40 square inches in 5 minutes. To find out how long it will take him to paint 226.19471 square inches, we can set up a proportion:

40 sq in / 5 min = 226.19471 sq in / x min

Cross-multiplying, we get:

40 * x = 5 * 226.19471

Simplifying further:

40x = 1130.97355

Dividing both sides by 40:

x = 1130.97355 / 40
x ≈ 28.274 minutes (rounded to the nearest minute)

Therefore, it will take Troy approximately 28 minutes to the nearest minute to paint the outside of the flower pot.