Answer:
Increase, 300%
Explanation:
36 inches is greater than 12 inches, therefore this is an increase. To find the percent of change, take the new amount, divide it by the original amount and multiply the result by 100 to get the percentage.
36/12 · 100 ⇒ 3 · 100 ⇒ 300
Therefore, the percent of change is 300%.