8. (3%) How many bit strings are there containing exactly five 0s and fourteen Is if every0 must be immediately followed by two ls? (A) 112 (B) 124 (C) 126 (D) 132

11. (3%) Let x= a+ bk be the solution of the system of congrucnces x = 7 (mod 9), x≡ 4 (mod 12),and x≡16 (mod 21), where a and b are the smallest positive integer, k e Z. Which is the correct value of (2a+b) mod 11? (A)9 (B) 7 (C) 4 (D) 6