RD Sharma - Mathematics (Volume 2)

Book: RD Sharma - Mathematics (Volume 2)

Chapter: 33. Binomial Distribution

Subject: Maths - Class 12th

Q. No. 25 of MCQ

Listen NCERT Audio Books to boost your productivity and retention power by 2X.

25

Mark the correct alternative in the following:

The probability of selecting a male or a female is same. If the probability that in an office of n persons (n – 1) males being selected is , the value of n is


Given:


P(females)=p(males)=1/2


p(x=n-1) =


n=?


p(x=n-1) = nCn-1 pn-1 q1


Since p=q


p(x=n-1)= n pn-1q


=n pn-1p


=npn


=n





comparing LHS anr RHS


we have,


n=12

Chapter Exercises

More Exercise Questions