prob & stat
posted by jay .
An academic department with five faculty members—Anderson, Box, Cox, Cramer, and Fisher—must select two of its members to serve on a personnel review committee. Because the work will be time-consuming, no one is anxious to serve, so it is decided that the representative will be selected by putting the names on identical pieces of paper and then randomly selecting two.
(a) What is the probability that both Anderson and Box will be selected?
answer 0.1 or 1/10
(b) What is the probability that at least one of the two members whose name begins with C is selected?
answer 0.7 or 7/10
(c) If the five faculty members have taught for 3, 6, 7, 10, and 14 years, respectively, at the university, what is the probability that the two chosen representatives have a total of at least 14 years teaching experience there?
I need answer for C? Don't understand.
prob & stat -
6, 10 or 6, 14
7, 10 or 7, 14
It looks like there are 6 possibilities that meet this criteria because they all add up to at least 14 which means 14 or more years
If we choose two out of 5
Use a combination of 2 chosen from 5 which is 5!/(3! 2!) = 10 choices
! means multiply down to 1. So, 5! means 5 x 4 x 3 x 2 x1.
You had 6 possibilities out of 10 choices or .6