How Do I Get into the Casino?

1. You wouldn't want to use the main entrance. You're avoiding the detective, and you feel even worse about the sheriff with him.

2. There is another door.

3. And it requires a passcode—of course.

4. Take a closer look at the keypad.

5. Notice the yellow dust on some keys?

6. Someone with dusty hands must have just got in.

7. Even better than fingerprints, right?

8. If only you knew the sequence.

9. Have you tried asking someone?

10. The man on the motorcycle might know.

11. You just need to solve his riddle. Easy.

12. A prime number is a number that can only be divided by 1 and itself.

13. There are only four 2-digit prime numbers you can make out of 2, 3, 6 and 7.

14. And only two if you're going to press each dusty key once.

15. Now it's only a matter of which one comes first, and which one second.

(SOLUTION FOLLOWS)

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16. The code is 6723.