1. Write the following sets in roster notation: (a) {a a N and 3a +1 < 20} (b) {3a+1 aN and a 6} 2. Write the following sets in set-builder notation. There may be more than one correct representation; but your representation must restate membership in the set in some way. (a) {11,6,1,-4,-9,-14,...} (b) {1 248 3'9' 27' } 3. Define the following sets: A = {a,b,c,d} B={d, e, f, g, h} C= {b, c, e, f,i} D= {a, j, k, l, m} Determine whether each of the statements is true, false, or meaningless. State your answer clearly. (You do not have to justify your answers, but they have to be correct.) (a) a D (b) D= B (c) {d, h} CB (d) D = C (e) |D| = |C|