Part A
In how many ways can they arrive?
Find out the permutation P5
[tex]\begin{gathered} P5=5!=5*4*3*2*1 \\ P5=120 \end{gathered}[/tex]Part B
In how many ways can Katrina arrive first and lan last?
1) Katrina
2) Maria, Sergio, Larry (3)
3) Maria, Sergio, Larry (2)
4) Maria, Sergio, Larry (1)
5) Ian
the number of ways is=(1)(3)(2)(1)(1)=6
Part C
Find the probability that Katrina will arrive first and lan last.
P=6/120
simplify