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.