ex04-ec0.rb

cars = 100
space_in_a_car = 4.0
drivers = 30
passengers = 90
cars_not_driven = cars - drivers
cars_driven = drivers
carpool_capacity = cars_driven * space_in_a_car
average_passengers_per_car = passengers / cars_driven

puts "There are #{cars} cars available."
puts "There are only #{drivers} drivers available."
puts "There will be #{cars_not_driven} empty cars today."

# Zed added an underscore in between 'car' and 'pool', thereby referring 
# to a variable that wasn't defined.
puts "We can transport #{car_pool_capacity} people today."

puts "We have #{passengers} passengers to carpool today."
puts "We need to put about #{average_passengers_per_car} in each car."