Answer:
3/4
Step-by-step explanation:
probability of any event = ![\frac{number of favourable outcomes}{total number of outcomes}](https://tex.z-dn.net/?f=%5Cfrac%7Bnumber%20of%20favourable%20outcomes%7D%7Btotal%20number%20of%20outcomes%7D)
3 freshmen + 3 sophomores + 3 juniors + 3 seniors = 12 participants
∴the total number of participants = 12
P(freshman is a captain) = ![\frac{number of freshmen}{total number of participants}](https://tex.z-dn.net/?f=%5Cfrac%7Bnumber%20of%20freshmen%7D%7Btotal%20number%20of%20participants%7D)
=
=![\frac{1}{4}](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B4%7D)
P (freshman is not a captain) = 1 - ![\frac{1}{4}](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B4%7D)
= ![\frac{3}{4}](https://tex.z-dn.net/?f=%5Cfrac%7B3%7D%7B4%7D)
whenever the probability of an event not happening is being calculated, always subtract the possibility of the occurrence of such event from 1