If length of rectangle of increases by 20% and breadth decreases by20%. Then the area decreases by how much?

Question

options are
a> decreases by 4%
b>decreases by 2%
c> none

Answer 1

If the length is L and the width is W, the area is LW. The new length is 1.2L and the new width is 0.8W, making the new area (1.2L)(0.8W) = 0.96LW. This is 96% of the original area, so it has decreased by 4%. Answer A).

Answer 2

let length=100%
and breadth =100%
=> area = 100 *100= 10000

let length=120%
and breadth =80%
=> area =120 * 80=9600

area decreases =400
% decrease = 400/10000 * 100%
% decrease = 4%

Ans = a> decreases by 4%

Answer 3

Let the length be 10x units and the breadth be 10y units
The present area is 100xy units square.after changes,the length is 12x units and the breadth is 8y units.
Therefore,the new area is 96 units square
Hene there is a decreae of 4%