25) percent of area

Question

If one pair of opposite sides of a square are increased in length by 20% and the other pair of sides are increased in length by 50%, by what percent is the area of the rectangle that results greater than the area of the original square?

Answer 1

Let x = length of a side of the original square

 

One dimension of rectangle = x + 0.2x = 1.2x

 

Other dimension of rectangle = x + 0.5x = 1.5x

 

Area of rectangle = (1.2x)(1.5x) = 1.8x = x + .8x

 

The area of the rectangle is 80% greater than the area of  the square.