Determine the number of 6 digit positive integers combinatorics there is at least one 7

Can find this by finding the number of 6 digit positive integers w/o 7, then subtracting that from the total number of 6 digit postive integersnumber of six digit positive integers  that do not contain 7: there are only 8 digits for the first digit because you cannot have 0 (makes it a non-six-digit number) and cannot have 7. there are 9 digits for the rest of the digits (no 7).total number of six digit positive integers (no zero for the first digit):   number of six digit positive integers  that contain at least 7 is the total number of six digit positive integers  minus the number of six digit positive integers  that do not contain 7.

C. divide 2205 by 49 and you will get 45 and 45 is c