Question: 1. Encrypt the message it was a dark and stormy night using the original Vigen`ere cipher with key word weather.
2. Find χ(G) and χ(G) for the graph shown at left in Figure.
3. Let f: N×N → N, with f(a,b) = 2a · 3b. Decide (with proof) whether f is one-to-one, onto, both, or neither.
4. Is 9 ≡ 3 (mod 6)? What about 389 ≡ 87 (mod 92)?