1 Let a be a unit mod N, and b a zero divisor mod N. Then mod N, ab is a unit a zero divisor neither 2 Give a big- estimate for logn! (logn) (n log n) en3/2) e(n) 3 Let N > 3. If 17N-1 1(mod N), then N is not a prime. true false undecided 4 Convert the hexadecimal expansion (BAD) . into a decimal integer. 5 Determine 231 (mod 17) 6 Determine -55 (mod 17) 7 Determine 6(143) 8 Determine 2123 mod 55 Give a big-8 bound for the solutions of the following recurrence relations. 9 T(n) = 9T(n/2) + 100m2 10 T(n) = 9T(n/3) + inn