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 drives for Uber, 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. Input pure numbers, such as "56", with no dollar signs or quotation marks. The private marginal cost per hour spent driving is. The external marginal cost per hour spent driving is.