An urn contains 6 red balls numbered 1, 2, 3, 4, 5, 6, and 4 black balls with numbers 7, 8, 9, 10.We select three balls from the urn randomly and without replacement. For each of the following variables, find the probability function and its expectation:

(i) the number of red balls selected,

(ii) the number of black balls selected,

(iii) the largest number on the balls chosen,

(iv) the smallest number on the balls chosen.