"Password": Why are there ten digits instead of 9?

Link

http://gre.magoosh.com/questions/849

Question

Why are there ten digits? There are only 9 numbers in 1-9.

Answer

Remember that 0 can be used anywhere in this password. 0-9 gives us ten digits which can go anywhere, including in the first position because the password is not a number, just a series of digits.

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