1. Consider bitstrings of length 13. The positions in these strings are numbered as 1, 2, 3, ...,13. How many such bitstrings have the property that all bits at the odd positions are equal? (a) 32 (b) 64 (c) 128 (d) 256 2. Consider permutations of the set {a,b, c, d, e, f,g} that do not contain bge (in this order). How many such permutations are there? (a) 7! 6! (b) 7! 5! (c) 7! 4! (d) 7! 3! 3. Consider strings of length 15, where each character is a lowercase letter or an uppercase letter. How many such strings contain at least one lowercase letter and at least one uppercase letter? (a) 5215 2615 (b) 5215 2 2615 (c) 5215 3 2615 (d) None of the above 4. Let n>8 be an even integer and let k be an integer with 2