[rv_blitz]

Security Geek,
This is a great compilation.

An alternative way 2 solve this problem.

31. If Bob and Jen are two of 5 participants in a race, how many different ways can the race finish where Jen always finishes in front of Bob?



answer : Total number of ways of arranging 5 participants = 5! = 120.
In, half of these arrangements Jen will finish ahead od Bob .
So, no of arrangements = 120/2 = 60