Discrete mathematics Please clear hand writing and full explanation with steps so i can study them

Q2: 2!) i. Let U = {n 6 2+ | n S 10} be the universal set and Let A = {ne U | 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). b) If I 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? C) A quiz has 5 multiple-choice questions. Each question has 4- answer choices, of which 1 is correct answer and the other 3 are incorrect. Suppose that you guess all the answers. i. How many ways are there to answer the 5 questions? ii. What is the probability of getting all 5 questions right? iii. What is the probability of getting exactly 4 questions right? iv. What is the probability of getting at least 4 right