A 12-ft-by-15-ft rectangular swimming pool has a 3-ft-wide-no-slip surface around it. What is the outer perimeter of the no-slip surface?

78 ft
78 ft^2
198 ft
198 ft^2

I've already completed it, and know the answer is 78 ft, but I don't quite understand it. I would appreciate if someone could explain the problem. I thought it would have been +3 to each side, so 12 ft becomes 15 ft, and the other side, which is 15 ft, will be 18 ft. This is incorrect though, so I'm confused.

Thank you!

it's 3 ft on each side (left&right, top&bottom), so 12 becomes 18, 15 becomes 21.

2(18+21) = 78

Thank you for the explanation.

Well, it seems like you're slipping up a bit with your calculations there! But never fear, Clown Bot is here to help you understand.

Let's break it down step by step. The pool itself is 12 ft by 15 ft, and you're correct that if you add 3 ft to each side, it would become 15 ft by 18 ft. However, that's not the outer perimeter of the no-slip surface.

To find the outer perimeter of the no-slip surface, you actually need to add the distance around all four sides of the 15 ft by 18 ft shape. So, it would be 15 ft + 18 ft + 15 ft + 18 ft. Let's do the math:

Perimeter = 15 ft + 18 ft + 15 ft + 18 ft
Perimeter = 51 ft + 33 ft
Perimeter = 84 ft

Ah, it looks like the correct answer is 84 ft, not 78 ft like you thought. Sometimes, numbers can be a bit slippery! Keep practicing, and I'm sure you'll get the hang of it.

To find the outer perimeter of the no-slip surface around the swimming pool, we need to consider the dimensions of both the pool and the no-slip surface.

The rectangular swimming pool is given to be 12 ft by 15 ft. This means the length of the pool is 12 ft and the width is 15 ft.

The 3-ft-wide no-slip surface extends around the pool, so we need to add 3 ft to each side of the pool to account for the no-slip surface.

When adding the 3 ft to each side of the pool, it is important to remember that we are adding extra length on all four sides, so we should increase both the length and the width of the pool by 3 ft.

Therefore, the dimensions of the rectangular pool with the no-slip surface would be 12 ft + 3 ft + 3 ft = 18 ft and 15 ft + 3 ft + 3 ft = 21 ft.

Now we can calculate the outer perimeter of the no-slip surface by adding up all four sides of the rectangle:

Perimeter = 2 * (Length + Width)

Substituting the values, we get:

Perimeter = 2 * (18 ft + 21 ft)
Perimeter = 2 * 39 ft
Perimeter = 78 ft

Hence, the outer perimeter of the no-slip surface around the swimming pool is 78 ft.