Max plus min is the sum

Let $X_1,X_2$ denote lifetimes (in years) of 2 components of an electronic system. Let $Y_1=X_1+X_2,Y_2=\max${$X_1,X_2$} and $Y_3=\min${$X_1,X_2$}. Assume that $X_1$ and $X_2$ are independent, each following exponential distribution with probability density function f(x) = (1/2)e^(−x/2) if x > 0, and 0 otherwise. Which of the following statements are true?