Veronica works each day and earns more money per hour the longer she works. Write a function to represent a starting pay of $20 with an increase each hour by 5%. Determine the range of the amount Veronica makes each hour if she can only work a total of 8 hours.

20 ≤ f(x) ≤ 28.14
20 ≤ f(x) ≤ 29.55
20 ≤ f(x) ≤ 26.80
20 ≤ f(x) ≤ 25.53