SOLUTION: The Student number at a University consists of 2 letters, followed by 4 digits followed by 2 letters. How many different student numbers are possible if: a. Letters and digits ca

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Question 347994: The Student number at a University consists of 2 letters, followed by 4 digits followed by 2 letters. How many different student numbers are possible if:
a. Letters and digits cannot be repeated.
b. Letters can be repeated, but digits cannot
Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
a. 26*25*10*9*8*7*24*23=1,808,352,000 combinations without repeats.
b. 26*26*10+9*8*7*26*26=2,303,159,040 combinations with only letter repeats.