The prbability that a student is not a swimmer is 1/5. Then find the probability that our of 5 students exactly 4 are swimmer.

Answer

`((4)/(5))^(4)`

Explanation

Let p be the probability that a student selected at rondom is a swimmer, which is given by `1-1//5=4//5.` The number of students selected is 5. Probability that exactly 4 students are swimmers is
`""^(5)C_(4)p^(4)q=5((4)/(5))^(4)((1)/(5))=((4)/(5))^(4)`