Explanation:
To compute the area of the outer dark gray strip, you'll need to know the dimensions of the inner light gray strip. Since the inner strip has a width of 1 inch on all sides, you can subtract 2 inches from both the length and width of the outer frame to find the dimensions of the inner strip.
Let's denote the length of the inner strip as L inches and the width as W inches. Then, the dimensions of the outer frame would be (L + 2) inches for the length and (W + 2) inches for the width.
Since the area of the inner light gray strip is 100 square inches, you can set up an equation:
L * W = 100
Now, you can find the area of the outer dark gray strip:
Outer strip area = (L + 2) * (W + 2) - L * W
Substitute the value of L * W from the equation above:
Outer strip area = (L + 2) * (W + 2) - 100
You'll need the specific values of L and W to calculate the exact area of the outer dark gray strip.