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Question
Three persons enter into a conference hall in which there are 10 seats. In how many ways they can take their seats?
Solution
Number of seats in the conference hall = 10
Number of persons entering into the conference hall = 3
Number of ways of getting a seat for 1st person = 10
Number of ways of getting a seat for 2nd person = 9
Number of ways of getting a seat for 3rd person = 8
By fundamental principle of multiplication
Number of ways of getting seats for 3 persons in conference hall = 10 × 9 × 8 ways = 720 ways
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