Three-digit positive integers such as 789 and 998 use no digits other than 7,8 and 9. In total, how many three-digit positive integers use no digits other than 7,8 and 9?
Answer Choices
A. 36
B. 6
C. 9
D. 18
E. 27
Three-digit positive integers such as 789 and 998 use no digits other than 7,8 and 9. In total, how many three-digit positive integers use no digits other than 7,8 and 9?
Answer Choices
A. 36
B. 6
C. 9
D. 18
E. 27