The sum of all 4 digit numbers that can be formed by using the digits 2, 4, 6, 8. (repetition of digits not being allowed) is -

To solve this problem, we need to understand that each digit will appear in each position (thousands, hundreds, tens, ones) the same number of times.

Step 1: Calculate the total number of 4-digit numbers that can be formed with the digits 2, 4, 6, 8. Since repetition is not allowed, we have 4 options for the first digit, 3 options for the second digit, 2 options for the third digit, and 1 option for the last digit. So, the total number of 4-digit numbers is 432*1 = 24.

Step 2: Calculate the sum of the digits, which is 2 + 4 + 6 + 8 = 20.

Step 3: Each digit will appear in each position (thousands, hundreds, tens, ones) the same number of times. So, the sum of all these numbers is 20 (sum of digits) * 1111 (because each digit will appear in each position) * 24 (total number of 4-digit numbers) / 4 (because each digit will appear in each position the same number of times).

So, the sum of all 4-digit numbers that can be formed by using the digits 2, 4, 6, 8 is 20 * 1111 * 24 / 4 = 132,660.