logo

Ask Questions, Get Answers

 
X
 Search
Want to ask us a question? Click here
Browse Questions
Ad
Home  >>  CBSE XI  >>  Math  >>  Permutations and Combinations
0 votes

There are 5 letters and 5 different envelopes.The number of ways in which all the letters can be put in wrong envelope is

$\begin{array}{1 1}(A)\;119\\(B)\;44\\(C)\;59\\(D)\;40\end{array} $

Can you answer this question?
 
 

1 Answer

0 votes
Toolbox:
  • $n!=n(n-1)(n-2)(n-3)....(3)(2)(1)$
Total no. of letters =5
Total no. of envelopes =5
Required numbers =$5!\big[1-\large\frac{1}{1!}+\frac{1}{2!}-\frac{1}{3!}+\frac{1}{4!}-\frac{1}{5!}\big]$
$\Rightarrow 120\big[1-\large\frac{1}{1}+\frac{1}{2}-\frac{1}{6}+\frac{1}{24}-\frac{1}{120}\big]$
$\Rightarrow 44$
Hence (B) is the correct answer.
answered Jun 20, 2014 by sreemathi.v
 

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
...