Question

A towel, when bleached, lost 20% of its length and 10% of its breadth. What is the percentage decrease in area? *
a) 26%
b) 28%
c) 30%
d) 32%​

Answer 1

Let the length be x units

and the breadth be y units

 Area = Length x Breadth = xy units²

 20% decrease = 20% of x = 0.2x

New length = x - 0.2x = 0.8x units

Find the new breadth:

10% decrease = 10% of y = 0.1y

New Breadth = y - 0.1y = 0.9y units

Find the new area:

Area = Length x BreadthFind the

Decrease = xy - 0.72xy = 0.28xy units

Decrease percentage = (0.28xy ÷ xy) x 100 = 28%

Answer: The area is decreased by 28%