Question
a group of hockey officials consists of 6 referees and 5 linesmen. the probability that the youngest referee and linesman would be selected if one referee and two linesman are required is
a) 1/15 b)1/30 c) 1/60 d)1/120
a) 1/15 b)1/30 c) 1/60 d)1/120
Answers
Damon
probability of youngest ref = 1/6
probability of NOT youngest linesman picked first = 4/5
then probability of NOT youngest linesman chosen second = 3/4
product of those = 4/5*3/4 = 3/5
so probability of youngest linesman chosen = 1-3/5 = 2/5
1/6*2/5 = 1/15
probability of NOT youngest linesman picked first = 4/5
then probability of NOT youngest linesman chosen second = 3/4
product of those = 4/5*3/4 = 3/5
so probability of youngest linesman chosen = 1-3/5 = 2/5
1/6*2/5 = 1/15