Donovan has two options to get to a party on the coast. He can either take an Uber or ride the bus. The Uber will cost him $45 and it will take one hour to get to the party. The bus will only cost $5 but it will take him three hours to get to the party. How much does Donovan have to value his time per hour to make him willing to use an Uber instead of taking the bus? Fill in the dollar amount below. No need to include a "$" sign.

Answer: $[ ]per hour