Answer:
The answer is 10%
Step-by-step explanation:
Let the length of the rectangle is x
Let the width of the rectangle is y
∵ They will increase by 10% each
∴ The new length = x × 110/100 = 1.1x
∴ The new width = y × 110/100 = 1.1y
∵ The old perimeter = 2(x + y) = (2x + 2y)
∴ The new perimeter = 2(1.1x + 1.1y) = 1.1(2x +2y)
∴ The new perimeter is greater than the old perimeter by 1.1 - 1 = 0.1
∴ The percentage of increasing in the perimeter = 0.1 × 100 = 10%
