Given the four digits 2, 4, 6, and 7, how many different positive two-digit integers can be formed using these digits if a digit can be repeated in an integer?
+130077 For numbers with different digits we want to permute 2 choices out of 4 = 12
Plus the repeated digit numbers = 4
So
12 + 4 = 16 integers
+146 
+37157 4 choices for first digt x 4 choices for second digit = 16 possibilities.
