Hi, please help me explain the answer of c) and d). I am so confused about this two questions. Thank you so much!

Question 1 [13 marks] Dirk likes having coffee and biscuits everyday. Let X denote the number of cups of coffee Dirk drinks on any given day. The number of cups of coee Dirk drinks is independent from day to day. Let Y denote the number of biscuits Dirk eats on any given day. The number of biscuits Dirk eats is independent from day to day. The relationship between X and Y is described by the following joint probability distribution: y (Biscuit) 3 4 6 3 0.12 0.25 0.04 I (Coffee) 0 0.14 0.20 0.02 7 0.10 0.05 0.08 (a) [3 marks] Find the probability that Dirk drank 3 cups of coffee today, given that he ate more than 3 biscuits. Solution: 0.4531 (b) [3 marks] Find the probability that Dirk ate 3 biscuits today, given that he drank more than 3 cups of coffee. Solution: 0.4068 (e) [4 marks] lO'Ver the next 10 days, nd the probability that Dirk drank more than 3 cups of ooffee on more than 7 days. Solution: 0.1517 (d) [3 marks] lO'ver the next 30 days, nd the probability that Dirk drank more than 3 cups of coffee on more than 20 days. Solution: 0.1977