A 20 sided die has each face marked with a different integer

A 20 sided die has each face marked with a different integer from 1-20. Assume each face is equally likely to occur on a single roll, the outcome is a random variable X~DU(20).

a) If the die is rolled twice, find the pdf of the smallest value obtained, say Y.

b) If the die is rolled three times, find the probability that the largest value is 3.

c) Find E(X) and Var(X)

Solution