logo

Ask Questions, Get Answers

 
X
 Search
Want to ask us a question? Click here
Browse Questions
Ad
Home  >>  JEEMAIN and AIPMT  >>  Mathematics  >>  Class12  >>  Probability
0 votes

Two persons A and B have equal number of sons. There are three cinema tickets which are to be distributed among the sons of A and B. The probability that all the tickets go to sons of A is $ \large\frac{1}{20}$. The number of sons each of them is :

$\begin {array} {1 1} (1)\;3 & \quad (2)\;4 \\ (3)\;5 & \quad (4)\;6 \end {array}$

 

Can you answer this question?
 
 

1 Answer

0 votes
Lt each have $x$ rows
$ \therefore $ Probability that all the tickets go to the rows of A = $ \large\frac{xc_3}{2xc_3}$
$ \Rightarrow \large\frac{x(x-1)(x-2)}{2x(2x-1)(2x-2)}= \large\frac{1}{20}$
$ \Rightarrow x = 3$
Ans : (1)
answered Jan 3, 2014 by thanvigandhi_1
 

Related questions

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