Sample space and Bridge game

[Win_odd Dhamnekar]

Bridge : For k= 1,2,3 ,4 let $\displaystyle N_k$ be the event that North has at least k aces. Let $\displaystyle S_k,E_k,W_k$ be be the analogous events for South, East, West. Discuss the number x of aces in West's possession in the events
a)$\displaystyle W_1'$
b) $\displaystyle N_2S_2,$

c) $\displaystyle N'_1S'_1E'_1$
d) $\displaystyle W_2 - W_3$
e)$\displaystyle N_1S_1E_1W_1$

f) $\displaystyle N_3W_1$
g)$\displaystyle (N_2 \cup S_2)E_2$

How to answer these questions? Truly speaking, I didn't follow these events. Would any member of math help board answer these questions along with explanation of these events?