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2021 AMC 12D Question 23

AMC12 · 2021 AMC 12D

Question 23

What is the average number of pairs of consecutive integers in a randomly selected subset of $5$ distinct integers chosen from the set $\{1, 2, 3, \ldots, 30\}?$ (For example the set $\{1, 17, 18, 19, 30\}$ has $2$ pairs of consecutive integers.)
  1. $\dfrac{2}{3}$
  2. $\dfrac{29}{36}$
  3. $\dfrac{5}{6}$
  4. $\dfrac{29}{30}$
  5. $1$