The joint probability distribution of the random variables is f(x,y)= 8xy, 0<=y<=x<=1. fine the covarience of x and y

Porphyrin is a pigment in blood and other body fluids that is significant in body energy and storage.  Let x be a random variable that represents the number of milligrams of porphyrin per deciliter of blood.  In healthy adults x is approximately normally distributed with μ = 38 and σ = 12.  What is the probability that x is less than 60?

A continuous random variable X is uniformly distributed between -5 and 5. What is the probability of measuring X = 2 exactly?

Let X be a Poisson random variable with rate X. Find the mgf of X.