Answer:
[tex]N=4(3)=12[/tex]
Explanation:
You can use box method to answer a problem of this type. Since it requires 2-digit numbers, draw two boxes. On the first box, you can select from 4 digits (5, 6, 7, 8) while on the second box you can only select 3 since repetition is now allowed. Finally, determine the number of arrangements by getting the product of the numbers inside the boxes.