how many even 4-digit numbers can be formed using the digits 0-9, if the first number cannot be 0

Question

how many even 4-digit numbers can be formed using the digits 0-9, if the first number cannot be 0

Answer 1

You have 4 positions and only the last position (the ones place) has to be even for the entire number to be even.

 

Since you can't use a zero in the first position, you have 9 choices for numbers.  You have 10 choices for the 2nd and 3rd positions each, and 5 choices for the last place (0, 2, 4, 6, 8)

 

9 x 10 x 10 x 5 = 4500