A random permutation of n objects is selected.
(a) What is the probability that no pair of objects lies in their initial positions (either exactly as they were or swapped) if n =3?
(b) What is the probability that no pair of objects lies in their initial positions (either exactly as they were or swapped) if n =4?
(c) Let n be an even number, say n D 2k. Let L be the (random) number of odd-numbered objects that are placed in odd-numbered positions. Give the name of the distribution of L, including all parameters. Also state the mean and variance of L.
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