Answer: 12% increase
Explanation: if you use the formula in the pic I’ve provided below, you can find the increase by first subtracting the old value (450) by the the new value which would be (500-450). Then, you divide the answer you got (50) by the old value once again, and you would get (50/450 = 0.11 *rounded) and 0.11 as a percent is 11%, so the percent increase it 11%.
(Hope this helps!)