Question

The probability that a student is not swimmer is `1/5`, Then he probability that out of five students, for are swimmers is

Options

• `5C_4 (4/5)^4 (1/5)`

• `(4/5)^4 (1/5)`

• `5C_1 1/5 (4/5)^4`

• None of these

Answer 1

`5C_4 (4/5)^4 (1/5)`

Explanation:

Probability that a student is not a swimmers = `1/5`

⇒ Probability that a student is a swimmers = `1 - 1/5 = 4/5`

Probability distribution of students who are swimmers = `(1/5 + 4/5)^5`

⇒ Probability that out of 5 students 4 are swimmers = `5C_4 (1/5)^1 (4/5)^4`