probability.

[tecklee89]

Four equally qualified runners, John, Bill, Edward and Dave, run a 100m sprint, and the order of finish is recorded.
What is the probability that dave wins and John places second?

Any people can help me to solve this? i know the answer is 0.083. How to get this number?
Thanks

 

[Loren]

If you were to consider all possibilities of finishes by actually listing them...

ABCD
ABDC
ACBD
ACDB
etc.

you will find that you have a total of 24 different ways to finish.
Out of those 24, there will be two cases in which they finish in the desired order.
2/24 = ???