In how many ways can 5 children stand in a queue?
To find: number of arrangements of 5 children in a queue.
Here, 5 places are needed to be occupied by 5 children.
Therefore any one of the 5 children can occupy first place.
Similarly, any 4 children can occupy second place and so on.
Lastly, there will be a single person to occupy the 5 position
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 5 different objects in 5 places is
P(5,5) =
= =
= 120.
Hence, this can be done in 120 ways.