Question 1030177
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A manager of a pizza parlor (which operates 7 days a week) allows each of 3 employees to select 1 day off next week. Assuming the selection is done randomly and independently. What is the probability that all three select different days?
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First  employee can select any of 7 days of a week;
second employee can select any of remaining 6 days of a week;
third  employee can select any of remaining 5 days of a week.

In all, there are 7*6*5 possibilities to select different days.

The full set of possibilities is {{{7^3}}}.

So, the answer is {{{(7*6*5)/7^3}}} = {{{(6*5)/7^2}}} = 0.612245.
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