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.