An hour of an Uber driver's time is valued at $10, which is the wage she could make as a remote data entry clerk if she did not drive during that hour. If she spends an hour driving for Uber instead, she spends $5/hour on gasoline. She also contributes $5/hour in health damages to city residents due to emissions and $5/hour in congestion costs for other drivers. Assume these are all the relevant costs. What is he private marginal cost per hour spent driving? What is the external marginal cost per hour spent driving