Length of a rectangle is increased by 10 % and breadth decreased by 10 % Then the area of a new rectangle is ?

New length = (110/100 l) units = (11 l)/10 units

New breadth = (90/100 b) units = (9 l)/10 units

New area = (11l/10 × 9b/10) sq. Units = 99lb/100 sq. units

Decrease in area = (lb- 99lb/100)sq units = lb/100 sq. units

Decrease in area = (lb/100 × 1/lb ×100) % = 1 %

Decrease by = 1 %