#### Answer

Increase; $33.\overline{3}\%$

#### Work Step by Step

It is an increase because 20, the end amount, is greater than 15, the original amount.
The percent change is the amount of change (the difference between the new amount and the original amount) divided by the original amount.
$\frac{20-15}{15}$
We use the order of operations to solve:
First, simplify above the fraction bar with subtraction: $\frac{5}{15}$
Next, we divide: $0.\overline{3}$
To convert to a percent, we multiply by $100$: $33.\overline{3}\%$