If the length of a rectangle is increased by 20% and its breadth is decreased by 20 then its area
Soln:- let the length of rectangle=x
and the breadth of rectangle=y
The area of rectangle=xy
According to Question,
the length of a rectangle is increased by 20%
Means, the length of a rectangle=x+x of 20%
=x+x×20/100
=x+x×1/5
=x+x/5
=6x/5
Again, the breadth of a rectangle is decreased by 20%
Means,
=y-y×20/100
=y-y××1/5
=y-y×/5
=4y/5
now area of new rectangle= length×breadth
= (6x/5)×4y/5
=24xy/25
change in area of rectangles= xy -24xy/25
=(25xy - 24 xy)/25
=xy/25
% change in area of rectangles= (xy/25)×100/xy
=100/25
=4 %
hence area of rectangle decrease 4 % .
Ans....
