Alberta Diploma Question For a particular four-digit bank code, the first and last digits must be odd, and the second digit cannot be 4. Digits cannot be used more than once. To determine the total number of different possible bank codes, a student showed the following calculation: a xbx cxd where a, b, c, and d refer to the number of possible values for the code's first, second, third, and fourth digits, respectively. The values of a, b, c, and d are, respectively, (There is more than one possible answer.) (Record all four digits of your answer as a list. Example: 4,6,4,7)