Hello,

How many even five-digit numbers are there?

The answer is 5*9*10^3

I have 5 places _ _ _ _ _

I thought for a number to be even, the last place needs to contain an even number (0,2,4,6,8) which are 5 possibilities.

The answer indicates that some other place only can have 9 choices, instead of 10 (0-9). I do not understand why.

The following part of the question is

How many five-digit numbers are there with exactly one 3?

Here I do not even know where to start.

Thanks for any help