The situation described involves a starting payment of $10 followed by an additional $15 for each hour of work. This scenario can be represented as a linear function because the total amount of money earned increases at a constant rate ($15 per hour).
The function can be expressed as: \[ y = 10 + 15x \] where \(y\) is the total earnings and \(x\) is the number of hours worked.
Since the relationship between the number of hours worked and the total payment is positive and linear, the best choice is:
a positive linear function.