combinations and permutations

Question

Tom and Jerry are hoping to be selected from their class of 27 as president and vice-president of the Social Committee (they just want the positions, but don't care which of the two is the president). If the three-person committee (president, vice-president, and secretary) is selected at random, what is the probability that Tom and Jerry would be president and vice president?

Round your answer to six decimal places.

Answer 1

With Tom & jerry as President and vice president we can form 25 different committees.

Overall we could form 27C3 committees.

Probability is 25/(25C3) = (1/117).