A self-serve car wash charges $5.44 to use its facilities, plus an additional $0.63 for each minute the customer is at the self-serve car wash. If Tiffany was at the car wash for 9 minutes, how much was she charged?
Tiffany spent 9 minutes at the car wash.
At $0.63 per minute, Tiffany was charged 9 * $0.63 = $<<9*0.63=5.67>>5.67 for the minutes she spent at the car wash.
To use the car wash, Tiffany paid $5.44 + $5.67 = $<<5.44+5.67=11.11>>11.11. Answer: \boxed{11.11}.