Let XXX and YYY be i.i.d. random variables with MX(t)=(0.2+0.8et)5M_X(t) = (0.2 + 0.8e^t)^5MX(t)=(0.2+0.8et)5. Find Var(X+Y)Var(X+Y)Var(X+Y).
0.8
3.2
6.4
12.8