Question

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. What is the probability that the locker code begins with a prime number? What is the probability that the locker code is an odd number?

Answer 1

Then I believe that the answer is 50 percent, because:
567 578 589 579 586 596 times 2 (if you change the positions of the last two numbers) equals 12 different ways starting with the 5, knowing that, means that equals 12 for the 6, 7, 8, and the 9.
12+12+12+12+12=60
And half of the answers are gonna end in odds number.