Classify each of the following random variables as discrete or continuous.
a) The time left on a parking meter
b) The number of bats broken by a major league baseball team in a season
c) The number of cars in a parking lot at a given time
d) The price of a car
e) The number of cars crossing a bridge on a given day
f) The time spent by a physician examining a patient
g) The number of books in a student's bag