Carter rode his bike 9/10 of a mile from his house to his grandmothers house. This means that the distance from Carter's house to his grandmother's house is 0.9 miles. On his way back home, he rode 3/8 of a mile before the tyre on his bike went flat. This means that he rode 0.375 miles before his tyre went flat. The distance he must walk before he gets home will be the total distance from home minus the distance that he rode. It becomes
