Problem 3. Classify the following formulas into logically equivalent groups. (Hint: Try using truth tables, or simplify using logical equivalences as given in Tables 6 and 7 in Section 1.3 of the textbook.) (a)p (b)-pvvr (c) (p) (r) (d) (q) (e) p (9V) (f) (p vr) (g) (p 9) (pr) (h)-pvqvr