Mr. Porter owns a house. When he first bought the house it was valued at d dollars. Since then, the value of the house has increased. Mr. Porter writes the equation below to express the current value of his house.
d + 0.21d = 1.21d
Mr. Porter claims that the value of his house has increased by 121%, since 1.21 is equal to 121%.
d + 0.21d = 1.21d
Decide if Mr. Porter is correct. If he is correct, enter 121 below. If he is not correct, enter the correct percent increase.