Answer:

A. 40 m

Step-by-step explanation:

The given are:

• w = 5 (the width is 5 m)
• l = 3w (the length is three times longer)

Before finding the perimeter, let's solve for the length first.

(Since the width is 5 m and the length is 3 times longer, that means the length is 3 times 5—the width— which is equal to 15.)

• l = 3w
• l = 3(5)
• l = 15

The length is 15 m and the width is 5 m.

Now that we have the values of the length and width, we can solve for the perimeter.

The perimeter of a rectangle:

• P = 2(l + w)

• P = 2(15 + 5)
• P = 2(20)
• P = 40

Thus, the perimeter of a rectangular playground, given that the width is 5 m and the length is three times longer, is 40 m.

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