Discrete mathematics Part A ) full steps and clear hand writing pleasePart B) i want tree diagram and full steps with probability

QZ : b) i. Let U = {n e 2"\" In :1 10} be the universal set and Let A = {nEU I n is composite}. List the elements of the set A. ii. Find in set builder notation the set of all positive integers a such that 131 E a (mod 5). If] ip a coin 20 times, I get a sequence of Heads (H) and tails (T). i. How many different sequences of heads and tails are possible? ii. How many different sequences have at most 2 heads? iii. How many different sequences have at least three heads