Question 1:

Let where Xi's be i.i.d. Normal with mean 10 and variance 4 for i=1,2,...,16 and Yj's be i.i.d. Normal with mean 15 and variance 12 for j=1,2,...,10 and Ix & Yj are independent for all i & j. What is the value of E[W] and Var(W)?

Question 2:

Let Y= where Xi's be i.i.d. Normal with mean 10 and variance 4 for i=1,2,...,32. What is the value of E[Y] and Var(Y)?

Two very similar problems, but I'm lost. The rest of the homework is spelled out very carefully with hints, and these two are just on their own. I don't even know where to begin.