# How many positive 3-digit integers can be formed using the digits 0, 1, 2, 3, 4, and 5?

My Question says, Using the digits (0, 1, 2, 3, 4, 5), how many positive 3-digit integers can be formed?

So my work so far is for positive 3 digit integers you would have the choice of 6 digits for the first digit, the choice of 6 digits for the second digit, and the choice of 6 digits for the third digit: (6)(6)(6)

But I'm not sure where to go from here, do I simply multiply them together? Is there another step afterwards? Am I missing something? Please help!

• If the first digit is $0$, does it still count as a three digit number? – Andrew Chin Nov 7 at 19:51
• There is also the possibility that the author meant that the digits are to be used without repetition, particularly if the numbers are expressed as the set $\{0, 1, 2, 3, 4, 5\}$. – N. F. Taussig Nov 7 at 20:36

The first digit cannot be $$0$$. Therefore the answer is $$5\times6^2$$.