The width of a rectangle is 6 2/3 inches. The length of the rectangle is twice its width. What is the perimeter of the rectangle

A perimeter of a rectangle is:
[tex]2(l+w)[/tex]

They give you the width, but let's convert it to an improper fraction first:
[tex]6 \frac{2}{3} = \frac{20}{3} [/tex]

The length is twice the width so it is:
[tex] \frac{20}{3}*2 = \frac{40}{3} [/tex]

Now, we are ready to solve, plug in values in the perimeter formula:
[tex]2( \frac{40}{3}+ \frac{20}{3}) = 2(\frac{60}{3}) = \frac{120}{3} = 40 [/tex]

So, 40 is your answer.