Answer:
24!
Step-by-step explanation:
I will refer the people to A,B,C, and D
24 is the answer.
4 choices for the first position.
3 choices for the second.
2 choices for the third.
1 for the fourth.
4*3*2*1=24
Here it is listed out where a,b,c,d are the 4 people:
abcd
abdc
acbd
acdb
adbc
adcb
bacd
badc
bcad
bcda
bdac
bdca
cabd
cadb
cbad
cbda
cdab
cdba
dabc
dacb
dbac
dbca
dcab
dcba
(of course, this assumes that there is a direction to the line, or a 'front' and a 'back'. If direction doesn't matter then the answer is 12, since every combination above has a reverse. e.g., abcd and dcba. The list becomes:
abcd
abdc
acbd
acdb
adbc
adcb
bacd
badc
bcad
bdac
cabd
cbad
