Question

If each of the dimensions of a rectangle is increased by 200%, the area is increased by

Options

• 300%

• 200%

• 800%

• 600%

Answer 1

800%
Explanation : 
Let dimensions of the rectangle are x and y respectively.
Then, Area = xy
After increment dimensions = (x + 200% of x) and (y + 200% of y)

= `(x+200/100x)and(y+200/100y)`

= 3x and 3y

= Then, new area = (3x) (3y) = 9xy

= Increment in area = 9xy - xy = 8xy

∴ Required percentage = `(8xy)/(xy)xx100`% = 800%