1. The problem statement, all variables and given/known data Twenty balls labelled 1 through 20 are put in a box. Eight balls are randomly selected from the box without replacement. Let x denote the largest number selected. (a) Denote by m the smallest possible value of x. Write down the value of m. (b) Let k be any integer such that m<=k<=20. Express P(x<=k) in terms of k. (c) It is known that x>15. Find the probability that x is 16. (Answers: (a) 8 (b) kC8 / 20C8 (c) 0.0538) 2. Relevant equations Probability Formulae 3. The attempt at a solution I know how to solve parts (a) and (b) but not part (c). I tried part (c) as follows: P(x=16) = P(x<=16) - P(x<=15) = (16C8 - 15C8) / 20C8 = 0.0511 However, the answer is not correct. Can anyone tell me how to solve it? Thank you very much!