Question

A kindergarten school has square mats in two colors, red and blue. The ratio of the perimeter of the red mat to the perimeter of the blue mat is 1 : 2. The area of the blue mat is 100 square feet.

What is the area of the red mat?

Answer 1

-25 square feet
-10 square feet
-75 square feet
-50 square feet

Answer 2

Once you get good at these, there's a quick way to do it, but it doesn't really make sense if you don't understand what's going on.

Try this: If the mats are square, what must the side length of the blue mat be to have an area of 100ft^2? Then what must the perimeter be? Then what must the perimeter of the red mat be? Then what are the side lengths of the red mat? Then what must the area of the red mat be?

If you can answer those questions in that order, you'll have your answer.

Answer 3

i got 25 square ft ?

Answer 4

That's right. Notice that if the perimeter is 2x as large, the area will be (2^2) times as large.

Answer 5

thanks