I am giving mock test and come across some questions which I feel wont be asked in the real exam, can anyone please confirm and try to solve this question.

1. Which of the following will not be a probability function?

a) X (1,2,3,4,5) p(x) = x/15

b) X (1,2,3,4,5) p(x) = 0.2

c) X (1,2,3,4,5) p(x) = (x*x)/55

d) X (1,2,3,4,5) p(x) = (10-x)/10

I am adding one more question which i encountered in the mock test, can u tell me if uch questions are asked.