Question

if length of a rectangle inceases by 15% and breadth decreases by 15%, then percentage change in area is

Answer 1

Let length be 10

And breadth be 10

Area 100

Now length is increased by 15%

New length 11.5

And breadth is decreased by 15%

New breadth is 8.5

New area is 97.75

Change in area 100-97.75 =2.25

percentage changed= 2.25% (decreased)

Answer 2

Area =xy

281.15x%29%280.85y%29
=281.15%29%280.85%29xy
=281.15%29%280.85%29A
=0.9775A


1-0.9775=0.0225

2.25% decrease in area