Question

A square length is increased by 20% and width is decreased by 20% . what is the % change in area

Answer 1

Assume the length and width of the square to be 100 units each.
Area of square =side × side= 100×100=10000 squ. units
When the length is increased by 20% and width is decreased by 20%
Now, the area becomes = 120×80 = 9600 squ. units
Therfore Area of square has decreased = 10000-9600= 400 squ. units
$Percentage \: of \: decrease \: = \frac{400}{10000} \times 100 = 4\%$