Need help with this question:

The joint probability mass function for random variables W and Y is in

the following table:

W=3 W=7 W=9

Y=2 0.2 0.05 0.05

Y=8 0.15 0.2 0.35

(a) (1.5pt) Compute the marginal probability mass function for W

(b) (1.5pt) Compute the marginal probability mass function for Y

(c) (2pt) Compute E(W) and V(W)

(d) (2pt) Compute E(Y) and V(Y)