Question

Find the percentage increase in the area of rectangle,if there is an increase of 10%in both length and breadth of a rectangle.​

Answer 1

Step-by-step explanation:

GIVEN:

Each sides of a rectangle are increased by 20%.

CONCEPT:

Area of rectangle is directly proportional to the product of length and breadth.

FORMULA USED:

Area of rectangle = Length × Breadth

CALCULATION:

Suppose the length and breadth of the rectangle are x and y respectively.

So, area of rectangle = xy

⇒ Increased length = 1.2x and Increased breadth = 1.2y

New area = 1.2x × 1.2y = 1.44xy

⇒ Increment in area = [1.44xy - xy] = 0.44xy

∴ Percentage increment in area = [0.44xy/xy] × 100 = 44%

Formula for successive percentage increment of x%

Percentage increase = x + x + xx/100

x = 20%

Percentage increase = 20 + 20 + 20 × 20/100 = 44%

∴ The percentage in area is 44%.