How many odd numbers can be formed using the digits $0, 4, 5, 7$? How many odd numbers can be formed using digits $0,4,5,7$.
I am getting answer $12$ but the actual answer is $14$. 

There are 24 permutations of the digits, six each starting with 0, 4, 5 and 7. Four digit numbers don't start with a 0, leaving 3 times 6 permutations. If the first digit is 5 or 7 then we remove the two numbers ending in 4, so 3x6 - 2x2 = 14. 
