A) Let X be a uniform random variable on the interval (0,2) and let Y be a uniform random variable on the interval (3,4). Suppose that X and Y are independent. Find the probability density function of X + Y.
B) Let X and Y be independent exponential random variables with parameters λ1 and λ2 respectively, where λ1 ?= λ2. Find the probability density function of X + Y.