Number of permutations of 1,2,3,4,5,6,7,8 and 9 taken all at a time ,such that the digit
1 appearing somewhere to left of 2
3 appearing to the left of 4 and
5 somewhere to the left of 6
(e.g.815723946 would be one such permutation)
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2 Answers
333total no of permutations are 9 factorial...
out of these,1 will be to the left of 2 half the times...apply this thrice,divide by 8,and u get the ans..
- Anonymous how 1 will be to the left of 2 half the times??Upvote·0·2015-11-22 09:32:16
486Is the answer 9!/8?
Swarna Kamal Dhyawala no it is 9x7!- Swarna Kamal Dhyawala plzz explain it who ever gets answer
- Niraj kumar Jha 9!/8 and 9*7! are the same thing.
- Swarna Kamal Dhyawala ooo sorry i saw opposite ...but how did u do
- Anonymous please explain your answer