The middle two digits MN are referred to as the group number. The group number can be any number from 01 to 99 (it cannot be 00). The last 4 digits ABCD are the serial number. The serial number can be any from 0001 to 9999 (it cannot be 0000). Additionally, the number social security number 123-45-6789 is only used in advertisements. How many social security numbers are possible? SHOW YOUR WORK IN THE SIMPLES WAY