A rectangle has a perimeter of 30 inches if the width is 3 times it's length find it dimension

Length = 11.25 and width = 3.75 inches.

Step-by-step explanation:

You must mean that the length is 3 times its width.

If the the width is x then the length is 3x inches.

Perimeter = 2*length + 2*width.

2 (3x) + 2x = 30

6x + 2x = 30

8x = 30

x = 3.75.

3x = 11.25.