Question

A towel, when bleached, lost 20% of its length and 10% of its breadth. what is the percentage decrease in area?

Answer 1

Let the length be x units

and the breadth be y units

Find the original area:

Area = Length x Breadth = xy units²

Find the new length

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 Breadth = (0.8x) ( 0,9y) = 0.72xy units²

Find the decrease percentage:

Decrease = xy - 0.72xy = 0.28xy units

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

Answer: The area is decreased by 28%

Answer 2

here is your answer OK dude


Let the length is l and breadth is b
Now the length becomes 0.8*l and breadth is 0.9*b
so the area=0.8*.9lb=.72 lb
So change in area=1-.72/1*100
=.28*100=28%

OK it help you.....