How many odd five-digit counting numbers can be formed by choosing digits from the set {1,2,3,4,5,6,7,8} if digits can be repeated?
+37165 To be odd, the number must end in 1 3 5 or 7 4 choices for the last position
8 choices for each of the other four positions
8 x 8 x 8 x 8 x 4 = .......
