There is a combination lock with four inputs 0-9. Can you figure it out?
The second isn't a 6.
Only one digit starts with a vowel.
The fourth is greater than the first, is greater than or equal to the third, and is greater than the second.
Either the first two numbers are even & the last two numbers are odd or vice versa.
The difference between the 1st & 2nd is the same as the difference between the 4th & 3rd (order matters).
One of the numbers is prime; three are composite.
