Ask Questions, Get Answers

Want to ask us a question? Click here
Browse Questions
Home  >>  CBSE XI  >>  Math  >>  Probability
0 votes

In a certain lottery 10,000 tickets are sold and ten equal prizes are awarded.What is the probability of not getting a prize if you buy two tickets

$\begin{array}{1 1}(A)\;\large\frac{9990C_2}{10000C_2}\\(B)\;\large\frac{9980C_2}{10000C_2}\\(C)\;\large\frac{9970C_2}{10,000C_2}\\(D)\;\large\frac{9000C_2}{10,000C_2}\end{array} $

Can you answer this question?

1 Answer

0 votes
  • $nC_r=\large\frac{n!}{r!(n-r)!}$
  • Required probability=$\large\frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}}=\frac{n(E)}{n(S)}$
Step 1:
Given total tickets =10,000
Out of which 10 tickets have prizes 9990 are blank
Total number of outcomes =$10000C_2$
Number of ways in which 2 tickets are without prize =$9990C_2$
Step 2:
$\therefore$ Required probability =$\large\frac{9990C_2}{10000C_2}$
Hence (A) is the correct answer.
answered Jul 2, 2014 by sreemathi.v

Related questions

Ask Question
student study plans
JEE MAIN, CBSE, AIPMT Mobile and Tablet App
The ultimate mobile app to help you crack your examinations
Get the Android App