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Explanation:
You can use the nCr formula shown below
[tex]_n C _r = \frac{n!}{r!*(n-r)!}[/tex]
where n = 39 and r = 1. However, you could also use the identity
[tex]_n C _{1} = n[/tex]
which basically says there are n ways to pick 1 item if you are given a choice of n items. In this specific case, we have 39 items total, and there are 39 ways to pick one item.
