Not sure why I'm getting the wrong answer for this question:

A box contains 5 salt shakers and 3 pepper shakers, each inside a plain cardboard container. If X is the number of containers opened by a person (who does not know the number of salt shakers in the box) searching for a salt shaker, make a table for the probability distribution for X.

The answer:

X | Pr[X=x]

1 5/8

2 15/56

3 5/56

4 1/56

Can someone please explain why the answer is the way it is?

Thanks