How many gallons of paint are needed to paint the walls of a rectangular prism shaped room that is 20 ft by 13 ft and 8 ft high if 1 gallon of paint covers 40 square feet?

20 Gallons of paint are needed.

Step-by-step explanation:

Surface Area of a rectangular prism formula is 2 * length * width + 2 * length * height + 2 * width * height.

Substituting the given values, we get:

SA = 2 * 20 * 13 + 2 * 20 * 8 + 2 * 13 * 8

SA = 1048

Area of the floor is length * width. 20 * 13 = 260

Subtract the area of the floor from SA as we do not paint the floor. 1048 - 260 = 788

The number of gallons of paint is 788 / 40 as each gallon covers 40 sq feet. We round this number up to ensure that we have more than enough paint. 788 / 40 = 19.7. Rounding that to 20.

Therefore, 20 gallons of paint are needed.

.632

step-by-step explanation:

6 * 1/10 = 3/5

3*0.01 = 0.03

3/5 + 0.03 = .63

2*0.002 = .002

.63 + 0.002 = .632