## Elementary Algebra

To find the percentage change, we use the following formula: Percent of change = $\frac{New\ amount\ -\ Original\ amount}{Original\ amount}$ $\times$ 100% The original amount is 500, and the new amount is 600. We substitute these values into the formula to obtain : percentage change = $\frac{600\ -\ 500}{500}$ $\times$ 100% percentage change = $\frac{100}{500}$ $\times$ 100% percentage change = 0.2 $\times$ 100% percentage change = 20%