The length and breadth of a rectangle are 20 m and 15 m respectively. If length is Increased by 20% and the breadth by 30%, the percentage increase in its area is

Explanation

Length of rectangle = l = 20 m and Breadth = b = 15 m => Area = A = l × b = (20 × 15) = 300 m2 20 Similarly, new length = l′ = 20 + ( 100 × 20) = 20 + 4 = 24 m 30 => New breadth = b′ = 15 + ( 100 × 15) = 15 + 4.5 = 19.5 m New area = A′ = 24 × 19.5 = 468 m2 (468−300) ∴ Increase in area = 300 × 100 168 = 3 = 56%