Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • NCERT
  • A die is thrown 5 times. Find the probability that an odd number will come up exactly three times.

A die is thrown 5 times. Find the probability that an odd number will come up exactly three times.

Answers (1)

Solution

Given-

n=5, Odd numbers = 1,3,5

\\p( odd number )=P(1)+P(3)+P(5) \\=\left(\frac{1}{6}+\frac{1}{6}+\frac{1}{6}\right) \\=\frac{3}{6}=\frac{1}{2}
and \mathrm{q}=1-\mathrm{p}=1-\frac{1}{2}=\frac{1}{2}
also,  r=3 
c\\ \therefore \mathrm{P}(\mathrm{X}=\mathrm{r})=\mathrm{n}_{\mathrm{c}_{\mathrm{r}}}(\mathrm{p})^{\mathrm{r}} \mathrm{q}^{\mathrm{r}} \mathrm{q}^{\mathrm{n}-\mathrm{r}} \\=^5C_{3}\left(\frac{1}{2}\right)^{3}\left(\frac{1}{2}\right)^{5-3} \\=\frac{5 !}{3 ! 2 !} \times \frac{1}{8} \times \frac{1}{4} \\=\frac{10}{32} \\=\frac{5}{16}

Posted by

infoexpert22

View full answer

Similar Questions

Latest Question