Each month, Allison gets a $15 allowance and earns $100 working at the theatre . She uses the expression 15x+100y to keep track of her earnings

International calls require the use of a country code. many country codes a 3-digit numbers. country codes do not begin with a 0 or 1. there are no restrictions on the second and third digits. how many different 3-digit country codes are possible?

Icould really use some with this question.

Can someone me out here and the tell me the greatest common factor