# jnu 2010

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## jnu 2010

 ques 36)in an examination there are three multiple choice questions and each question has 4 choices. number of ways in which a student can fail to get all the answers correct? ques 37) a function is selected at random from all the functions of the set A= (1,2,3,...N) in to self. the probability that the function selected is one to one is?
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## Re: jnu 2010

 36.no of ways= 4*4*4-1=63
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## Re: jnu 2010

 In reply to this post by manisha sachdeva There is only 1 way in which a student can answer all the questions correctly so no. Of ways in wich a student fail to get all the answers is the same as the no of ways in which he attempts atleat 1 ques  incorrectly so this is equal to total no. Of ways - 1(way in which all answers are correct) = 4^3-1 Akshay Jain Masters in Economics Delhi School of Economics 2013-15
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## Re: jnu 2010

 @Akshay plz have a look at this http://discussion-forum.2150183.n2.nabble.com/DOUBTS-td7589558.html "Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth."
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## Re: jnu 2010

 In reply to this post by manisha sachdeva Hi Manisha,Sample space= n^nf: A->A can be one-to-onewhen for f(1) we have 1..n .ie n choicesfor f(2)  n-1 choices......f(n). 1 choice  No. of one-one mappings possible= n(n-1)...1ie. ans is n!/(n^n) Rahul(p....u)On Tue, May 13, 2014 at 11:28 PM, manisha sachdeva [via Discussion forum] wrote: ques 36)in an examination there are three multiple choice questions and each question has 4 choices. number of ways in which a student can fail to get all the answers correct? ques 37) a function is selected at random from all the functions of the set A= (1,2,3,...N) in to self. the probability that the function selected is one to one is? If you reply to this email, your message will be added to the discussion below: http://discussion-forum.2150183.n2.nabble.com/jnu-2010-tp7589613.html To start a new topic under General Discussions, email [hidden email] To unsubscribe from General Discussions, click here. NAML "Woh mara papad wale ko!"
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## Re: jnu 2010

 In reply to this post by Anjali 37 n!/n^n
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