1) Determine whether (s^ (rs))r is a tautology. 2) How many of the disjunctions s V-u, svu, u V v, u V-v, and u Vv can be made simultaneously true by an assignment of truth-values to s, u, and v? 3) Determine whether each of these compound propositions is satisfiable. a) (rvs) ^ (r Vs) ^ (rV-s) b) (rs) ^ (rs) ^ (rs)^(s) c) (SV uvv) A (SVu VW) A (SVVVW)^(SVUVW) ^ (SV UVW)