Question

An artist drew a rectangle. the artist then modified the rectangle so thatthe length ofthe rectawngle increased by 30 percent and the width of the rectangle decreased by 40 percent. after the modification, what was the percent decrease in the area of the rectangle?

Answer 1

The dimensions of the original rectangle 
length - L
width - W
area = L*W = LW
after the modification, new dimensions are
length increased by 30 % 
Length = L * 1.3 = 1.3L
Width = W * 0.6 = 0.6W
new area = 1.3L * 0.6W
                = 0.78LW
the percent decrease in area 
decrease % = (difference in area)/original area * 100
                    = (LW - 0.78LW)/LW * 100
                    = 0.22LW/LW * 100
                    = 22%
percent decrease is 22%