PDA

View Full Version : probability of having the winning ticket for a raffle


rayray820
Jan 3, 2013, 10:55 AM
If 200 tickets are sold to win 1 of 2 TV's. If I bought 1 ticket, what are my chances of winning 1 of the TV's

ebaines
Jan 3, 2013, 11:10 AM
One way to approach this is like this: the probability of winning a TV is equal to the probabilty of (a) winning a TV with the first drawing, plus (b) the probability of losing the first drawing and winning the second.

Another way to approach it is to consider that the probability of winning a TV is 1 minus the probability of not winning a TV. The probability of not winning a TV is equal to the probability of losing on both the first and second drawings.

Both approaches give the same answer. I suggest that you try both and tell us what you get for an answer - we'll check it for you.

rayray820
Jan 3, 2013, 11:16 AM
One way to approach this is like this: the probability of winning a TV is equal to the probabilty of (a) winning a TV with the first drawing, plus (b) the probability of losing the first drawing and winnig the second.

Another way to approach it is to consider that the probability of winning a TV is 1 minus the probability of not winning a TV. The probability of not winning a TV is equal to the probability of losing on both the first and second drawings.

Both approaches give the same answer. I suggest that you try both and tell us what you get for an answer - we'll check it for you.

answer: Ok, that was a bit confusing, but I came up with this: the probabilty of winning one of the 2 TV's if 200 tickets were sold is 1% (2/200)= 0.01 X 100 = 1%

ebaines
Jan 3, 2013, 11:22 AM
That's correct.

rayray820
Jan 3, 2013, 11:35 AM
That's correct.

Cool, thanks