What are the probablities of winning a raffle with three numbers drawn and numbers can only be used once?

Question

What are the probablities of winning a raffle with three numbers drawn and numbers can only be used once?

Answer 1

by raffle, i assume you mean someone sold you a raffle ticket, if you mean "the #'s can only be used once" to mean that once a winning ticket is removed, it is not replaced.

the odds of winning would be 3 in (number of tickets sold)

if there was 100 tickets sold, a 3% chance

if there were 10,000 tickets sold. a .03% chance

Answer 2

I'm not sure I completely understand the question, but if the raffle is 0-9 and 3 different numbers are picked this is how you solve it.

no. possible draws: [(10!)/(1!)(9!)] + [(9!)/(1!(8!)] + [(8!)/(1!)(7!)]

=

(10*9*8*7*6*5*4*3*2*1)/(1)(9*8*7*6*5*4... + (9*8*7*6*5*4*3*2*1)/(1)(8*7*6*5*4*3*2*1) + (8*7*6*5*4*3*2*1)/(1)(7*6*5*4*3*2*1)

=10 + 9 + 8

=27 possible draws

You have one ticket, the probability you win the raffle is 1/27, or 3.7%