Hi everyone
I am having some trouble with the following questions. If anyone could help me out that would be great! Thanks a lot!

Here are the questions:
Let X represent the number of heads when a fair coin is tossed 20 times. Let Y represent the number of sixes that appear when a six-sided die is tossed 50 times. It is reasonable to assume X and Y are independent.
#1. What is the expected value of X + Y?
#2. What is the variance of X + Y?
#3. What is the standard deviation of X – Y?