Hint for Section 7.4 Question 2

2. The pigeonhole principle states that given a function, f, from the set X to the set Y, where n(X) > n(Y),  there must be at least two elements in the domain that have the same image in the co-domain.

Here let X be the set of people and Y be the set of combinations of first and last initials. What is the size of the set Y? Is the set X large enough to apply the pigeonhole principle?

Back to Section 7.4
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