Answer:
200%
Step-by-step explanation:
if you substitute in numbers you'll find this as the answer.
as an example:
suppose the sides of the rectangle was 1 unit long.
area before change: 1 * 1 = 1
then, the length gets increase by 50% making it 1.5 ( 50% of 1 is 0.5, then you add it onto 1, 1 + 0.5 = 1.5 )
the width gets increased by 100% making it 2 ( 1 + 1 = 2 )
new area: 1.5 * 2 = 3
1 increased by 200% is 3, therefore the answer is 200%