The length and the breadth of a rectangle are made to increase and decrease, respectively, by 8% and 10%. What is the percentage increase or decrease in its area?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. Decrease by 2.8%
The length of the rectangle = Increased by 8%
The breadth of the rectangle = Decreased by 10%
Area of a rectangle = Length × Breadth
Let the length and breadth of the rectangle be x and y respectively.
The initial area of the rectangle = xy
The final area of the rectangle = (108x/100)(90y/100) = 243xy/250
The decrease in area = xy - (243xy/250) = 7xy/250
The percentage = [(7xy/250)/xy] × 100% = 14/5%= 2.8%
The percentage of decrease in area is 2.8%