Solution
For this case we have 5 different people
And we want to find the number of possible combinations with the combination that Libbey or Lee cannot be next to Luke so we can do this:
Total of combinations:
5*4*3*2*1= 120
there are 2* 4! = 2*4*3*2*1= 48 combinations where Libbey would be next to Luke
And there are other 2*41= 2*4*3*"2*1= 48 combinations where Lee would be next to Luke
Then the possible combinations are:
120 - 48 -48 = 24
Then the best answer is :
D. 24