Question

Mary buys 20 tickets in a lottery that has 5000 tickets altogether find the probability that marry will win second price only?

Answer 1

so there is one first prize ticket, and one second prize ticket

Answer 2

mary wants the probability of winning second prize (but not first prize), correct?

Answer 3

yes

Answer 4

20 /5000 first prize and 19 /4999 is second

Answer 5

answer is 498/12475

Answer 6

so you want to know how they got that answer

Answer 7

yes plz

Answer 8

can you double check thats the answer

Answer 9

well what's the probability that the first prize won't be picked?

Answer 10

4980/5000 * 20/4999

Answer 11

no i just asked the probability that the first prize won't be picked. how much is that?

Answer 12

thats not what he got ,

Answer 13

4999/5000

Answer 14

alright and what's the probability that the second prize WILL be picked?

Answer 15

it depends on whether you pick the first prize ticket first or not

Answer 16

and what is that value?

Answer 17

1/ 4999

Answer 18

assuming you picked the first prize

Answer 19

alright then what's the probability that you didn't pick any of the other tickets afterwards?

Answer 20

what other prizes are there, it doesnt mention

Answer 21

there aren't any more. that's what the question tells us

Answer 22

Guys guys... I think you're looking at this from a wrong point of view. she has a 0.4% chance of winning a ticket. Factor that into your probability.

Answer 23

the probability of winning first prize is 1/5000 ,

Answer 24

srry my comp died yes the answer is right

Answer 25

ok i think i have an idea,

Answer 26

@ayeshaafzal221 you said "19 /4999 is second"

given that she did not win first place, why are her chances reduced by one?

Answer 27

if it asked for 2nd prize, the probability that triton says would be right. when asked ONLY first prize, that's when a lot more values get important

Answer 28

yes @Triton my bad

Answer 29

did you get it perl?

Answer 30

im not sure

Answer 31

ohk thank of trying guys , tomorrow i ll ask my teacher

Answer 32

but that's a 1 in 5000 chance :S

Answer 33

I have no idea how they got to that.

Answer 34

its tree diagram question

Answer 35

the first ticket, to get it was 20 out of 5000. to NOT get it was 4980/5000

Answer 36

the second ticket, to get it was 20 out of 4999, if the first one WASN'T picked. If it was, 19/4999 but it wasn't so it's the first value

Answer 37

since the 2nd ticket WAS picked, you only have 19 tickets, but since every ticket after that WASN'T picked you get for the third one, you have to get the probability that every ticket won't be picked after that.