Math

OOps....was out on a run with the doggies and realized I made a mistake here...it is now corrected...

We have 9 possibilities for the first digit

The Third digit can be 0-9 (ten possibilities)

Three possible for the second digit   0 2 4

with 0    9 of the digits (1-9) can be fourth digit

 with 2   the fourth digit can be 4 5 6 7 8 9 (six possibilities)

  and with 4   only  8 9 can be fourth digit       ( 6 or 8 cannot be the second digit because fourth needs to be 2x)

       0                           2                         4

9  * 1 * 10 * 9     +  9 * 1 * 10 * 6   +  9 * 1 *10 * 2  =   Well, I think you can do this math !