Answer:
Dee won
Step-by-step explanation:
Using < to mean "finished ahead of ", we are given ...
B = 3
D < B
D < C
A < C
D < A
Dee finished ahead of Air, Bart, and Caper, so Dee won the race.
_____
The order of finish must be D, A, B, C.
Formula for combinations:
(n!)/(r!(n-r)!)
For you, this is:
10!/(5!(10-5)!) = 10!/5!5! = (10•9•8•7•6•5•4•3•2)/(5•4•3•2)(5•4•3•2) = (10•9•8•7•6)/(5•4•3•2) = 30240/120=252 different ways.
1/20=.05 = 5%
Answer is 5%