If the initial fee is $20 and additionally $15 is charged per day, then the total amount is given by:
[tex]A=20+15x[/tex]Where "x" is the number of days and "A" the total amount to pay. Since the total amount is less than $110, then we have the following inequality:
[tex]20+15x\le110[/tex]This is the inequality that can be used to determine the value of "x".