Given :
Terry increased the size of his rectangular garden this summer. He increased to length by 50% and the width by 20%.
To Find :
By what percentage has his garden changed with these changes.
Solution :
Let, initial length and breadth is x and y.
So, initial area = xy .
Size after increasing them :
y' = y + 0.50y
y' = 1.5y
x' = x + 0.2x
x' = 1.2x
Final area = (1.5y)(1.2x) = 1.8xy
So, percentage increase is :
[tex]= \dfrac{new-original}{original }\times 100\%\\\\= \dfrac{1.8xy -xy}{xy }\times 100\\\\=80 \%[/tex]
Therefore, percentage increase in are is 80%.
Hence, this is the required solution.