d/f coes each consisting of 5 characters are to be generated. In each code the first two characters are A or B and the remaining three characters are any of the digits 0,1,2,...9 How many distinict codes be generated so? please tell me the answer

Answer 1

Whatever "d/f coes" are, the must look like
ABxxx, where x is one of the given digits.
I will assume that repetition is allowed.

no. of ways = (1)(10)(10)(10) = 1000

Answer 2

4000