If the length of a rectangle is increased by 25%, by what percentage should the width of the rectangle be decreased to maintain a constant area ?

Question

a. 5%
b. 10%
c. 15%
d. 20%
e. 25%

please answer and explain

Answer 1

L = Length

W = Width

25 % = 25 / 100 = 0.25

100 % = 100 / 100 = 1

100 % = 1 + 0. 25 = 1.25

A = L * W

1.25 * L * W * n = L * w Divide both sides by L * W

1.25 n = 1 Divide both sides by 1.25

n = 1 / 1.25

n = 0.8

0.8 = 80 / 100 = 80 %

100 % - 80 % = 20 %