The Total solution for NCERT class 6-12
The probability that a student is not a swimmer is 1/5. Then theprobability that out of five students, four are swimmers isA. 5C4 1/5 (4/5)4B. (4/5)4 (1/5)C. 5C1 1/5 (4/5)4D. None of these
A. 5C4 1/5(4/5)4
Explanation:
Let us assume Xrepresent the number of students out of 5 who are swimmers
Also, the repeatedselection of students who are swimmers are the Bernoulli trials
Thus, probability ofstudents who are not swimmers = q = 1/5
Clearly, we have X hasthe binomial distribution where n = 5
And, p = 1 – q
= 1 – 1/5
= 4/5