Answer: He get 24 miles before his tire went flat.
Explanation:
Let the number of miles he get before his tire went flat be 'x'.
Speed at which he left his house and rode his bike into town = 6 mph
Speed at which he got a flat tire so he had to turn around and walk his bike back to his house = 2 mph
Total time taken by the trip down and back = 16 hours
According to question,

Hence, he get 24 miles before his tire went flat.