Question

If the length of rectangle is increased by 25% and the width is decreased by 20%. Area of rectangle of equal to area of the square. Find what percent is changed in area of square?
1. e
2. 1
3. 2
4. 15

Answer 1

Correct Answer - Option 4 : 15

Given:

The length of rectangle is increased = 25%.

The breadth of rectangle is decreased = 20%.

Area of rectangle of equal to area of the square.

Formula used:

Area of rectangle = length × breadth

Area of square = (side)²

Calculation:

Let the length and breadth of rectangle be 'l' and 'b'.

So, area of rectangle = l × b

The length of rectangle is increased = l + 25% of l

⇒ The length of rectangle is increased = l + (25l)/100

⇒ (5l)/4

The breadth of rectangle is decreased = b – 20% of b

⇒ The breadth of rectangle is decreased = b – (20b)/100

⇒ (4b)/5

New area of rectangle = ((5l)/4) × ((4b)/5)

⇒ New area of rectangle = lb

Change in area of rectangle = lb – lb = 0

Area of square = area of rectangle 

So, change in the area of square = 0 %

∴ The percent is changed in area of square is 0% .