Q6 of 140 Page 296

Six students are contesting the election for the presidentship of the students, union. In how many ways can their names be listed on the ballot papers?

To find: number of arrangements of names on a ballot paper.


There are six contestants contesting in the elections.


Name of any 1 student out of six can appear first on the ballot paper.


2 position on the ballot paper can be filled by rest of the five names and so on.


Formula:


Number of permutations of n distinct objects among r different places, where repetition is not allowed, is


P(n,r) = n!/(n-r)!


Therefore, permutation of 6 different objects in 6 places is


P(6,6) =


= = = 720.


Hence, their name can be arranged in 720 ways.


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