Hexadecimal digits are 0, 1, 2, 3, 4,5, 6, 7, 8, 9, A, B, C, D, E, and F.
- How many hexadecimal strings of length twelve have five A’s andfive B’s?
- How many hexadecimal strings of length twelve have at mostthree E’s?
- How many hexadecimal strings of length twelve have exactlythree A’s and at least two B’s?
- How many hexadecimal strings of length twelve have exactly twoA’s and exactly two B’s, so that the two B’s are sandwiched betweenthe A’s? 00A0B8B8 111A is anexample of such string.
- How many hexadecimal strings of length twelve have six digitsfrom the set 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 and six digits from theset A, B, C, D, E, F? No repetition is allowed.
- How many hexadecimal strings of length twelve have four digitsfrom the set 0, 1, 2, 3, 4, 5, four digits from the set 6, 7, 8, 9,A and four digits from the set B, C, D, E, F?
- How many hexadecimal strings of length twelve have at leastthree distinct digits?
- How many hexadecimal strings of length twelve, have the sum ofall digits equal to 30? Allowed digits are 2, 3,..., 9
