a matching problem. 4 cards marked 1,2,3,4 are allocated at random to four positions also marked 1,2,3,4. a match occurs if a card and position number are identical. Let X be the number of matches. Calculate

1. E(X)
2. P(X greater than or equaL to one)

You can do this by writing out all the possible conditions and their number of matches. (there should be 4! = 24 cases).

The expectation is the average number of matches.

For the probability, you need to find the probability of getting 0 matches (from your table) and then doing 1 - this probability.

I'll happily check your answers for you if you come up with anything.