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Grade 12th passAlgebra

PERMUTATION AND COMBINATION
  1. IN HOW MANY WAYS CAN 21 BOOKS OF ENGLISH AND 19 BOOKS OF HINDI BE PLACED IN A ROW ON A SHELF SO THAT TWO BOOKS ON HINDI MAY NOT BE TOGETHER??

Profile image of ABHISHEK VASHIST
10 Years agoGrade 12th pass
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1 Answer

Profile image of Harsh Patodia
10 Years ago
Just place english books in 21! ways. Then between english books there are 23 gaps including ends so 19hindi book can pe placed in those 23gaps in 23P19 ways.
So total ways is 21! * 23P19 ways.