Any help on A, B, C set question would be greatly helpful. Thankyou A) How manysocial security numbe

Any help on A, B, C set question would be greatly helpful. Thankyou A)         How manysocial security numbers are possible if the first digit is 8? B)         How manybinary strings of length 8 begin and end with 10? C)         A, B, C arenodes on a computer network. There are 3 paths between A and B, 2between B and C, 1 between A and C. Along how many routes can amessage from A to C be sent? . . .