Marissa is designing a rectangular poster whose width is 2/3 of its height. Its perimeter will be 100 inches. what are the dimensions of the poster?

20 and 30, scroll down

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To find the dimensions of the poster, we need to set up and solve an equation based on the given information.

Let's assume the height of the poster is h inches. According to the problem, the width of the poster is 2/3 of its height. Therefore, the width is (2/3)h inches.

The formula for the perimeter of a rectangle is given by P = 2L + 2W, where P is the perimeter, L is the length, and W is the width.

Given that the perimeter of the poster is 100 inches, we can write the equation as follows:

100 = 2*(2/3)h + 2h

To simplify the equation, we can multiply both sides by 3 to eliminate the fraction:

300 = 2(2h) + 6h

Next, distribute and simplify the equation:

300 = 4h + 6h

Combining like terms, we have:

300 = 10h

Now, divide both sides by 10 to solve for h:

h = 300/10
h = 30

So, the height of the poster is 30 inches.

To find the width, we can substitute the value of h back into the equation for the width:

Width = (2/3)h = (2/3)*30 = 20 inches

Therefore, the dimensions of the rectangular poster are 30 inches (height) and 20 inches (width).