Arnold is concerned about his impact on the environment. currently he drives a car that only gets 12 miles per gallon of gas. which of the following would be the most effective measure to lessen his environmental impact?

Brian's school locker has a three-digit combination lock that can be set using the numbers 5 to 9 (including 5 and 9), without repeating a number. the probability that the locker code begins with a prime number is %. the probability that the last digit of the locker code is an odd number is %.