At 8:15 AM, Maya found a parking meter that still had 20 minutes until it expired. She quickly put a nickel, a dime, and two quarters in the meter and went shopping. If every 5 cents bought 15 minutes of parking time, at what time would the meter expire?
Maya put a nickel in the parking meter, which bought her 15 minutes of parking time. Therefore, the meter now had 20 + 15 = <<20+15=35>>35 minutes until it expired.
Maya put a dime in the parking meter, which bought her 2 * 15 = <<2*15=30>>30 minutes of parking time.
Now, the meter had 35 + 30 = <<35+30=65>>65 minutes until it expired.
Finally, Maya put two quarters in the parking meter, which bought her 2 * (15 minutes/5 cents) = 6 * 15 = <<2*(15/5)=6*15=90>>90 minutes of parking time.
Therefore, the parking meter would expire 65 + 90 = <<65+90=155>>155 minutes after 8:15 AM.
Keeping in mind that 60 minutes is equivalent to 1 hour, this is the same as 155 minutes / 60 minutes/hour = <<155/60=2.5833333333333335>>2.58 hours.
Thus, the parking meter would expire 2.58 hours after 8:15 AM, or at approximately 10:45 AM. Answer: \boxed{10:45}.