39this thread should help
have a look:
http://targetiit.com/iit-jee-forum/posts/derrangements-2904.html
Find the no. of ways of arranging 5 identical green, 4 identical blue and 3 identical yellow balls in a row such that none of the identical balls form a block (or in other words...comes serially :-).
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21 Answers
1Why 9 ???
give me the reason and i'll tell u the right answer.
39
49ohh se=ry...i tht all the blocks together form a block....:)
1Ans is :
(12!/5!4!3!) - [(10!/4!5!) + (9!/3!4!) + ((8!/3!4!)] + [7!/5! + 5!/3! + 6!/4!] - 3!
;-)...anyone getting the idea ???
1Nishant Sir and Prophet Sir are barred from solving this one !!!! ;-)
49even i am not 100% but most probably 95% this must be the answer!!
