Answer:
7 hours
Step-by-step explanation:
To find the remaining hours Katie can work, we call this unknown number x. We know she has already worked 13 hours so she will work for the whole week x+13. She cannot work more than 20 hours so we use the inequality sign less than or equal to.
[tex]x+13\leq 20\\x\leq 20-13\\x\leq 7[/tex]