Answer:
The first 4 guests can arrive in 32,760 ways.
Step-by-step explanation:
The order in which the guests arrive is important. For example, A,B,C,D is a different outcome to B,A,C,D. So we use the permutations formula to solve this question.
Permutations formula:
The number of possible permutations of x elements from a set of n elements is given by the following formula:
In this question:
4 guests from a set of 15. So
The first 4 guests can arrive in 32,760 ways.