Question

How many four digit numbers are there which are divisible by 2

Answer 1

To be divisible by 2, a number only needs to be even, meaning the units digit must be 0, 2, 4, 6, or 8.

For the first digit, it cannot be 0, so there are 9 options (1 to 9).
For the second, third, and fourth digits, they can be any digit from 0 to 9, so there are 10 options for each digit.

Using the multiplication principle, the total number of four-digit numbers that are divisible by 2 is 9 * 10 * 10 * 10 = <<9*10*10*10=9000>>9000. Therefore, there are 9000 four-digit numbers that are divisible by 2.