A question on Probability (1 Viewer)

goobi

Member
Joined
Oct 6, 2010
Messages
196
Gender
Male
HSC
2012
A girl has 5 tickets in a raffle in which there are 2 prizes and 40 tickets sold. Find the probability of her winning a prize.

So, I'm just wondering whether "winning a prize" actually means "winning exactly one prize" or "winning at least one prize".

Thanks for any help!
 

jamesfirst

Active Member
Joined
Jan 30, 2010
Messages
2,005
Gender
Male
HSC
2011
exactly means exactly 1 prize

at least means at least 1 prize... so can be 2 3 .............. prizes
 

goobi

Member
Joined
Oct 6, 2010
Messages
196
Gender
Male
HSC
2012
So which one, "winning exactly one prize" or "winning at least one prize", do you think is what the question asking for?
 

goobi

Member
Joined
Oct 6, 2010
Messages
196
Gender
Male
HSC
2012
Thanks...but why would it be "winning at least one prize"? If so, it implies that the event "winning all 2 prizes" is a subset of "winning a prize" as said in the question, which I think is a bit literally contradicting...
 
Last edited:

powlmao

Banned
Joined
Feb 17, 2011
Messages
3,970
Location
Hogwarts
Gender
Male
HSC
2012
A girl has 5 tickets in a raffle in which there are 2 prizes and 40 tickets sold. Find the probability of her winning a prize.

So, I'm just wondering whether "winning a prize" actually means "winning exactly one prize" or "winning at least one prize".

Thanks for any help!
At least one prize
 

powlmao

Banned
Joined
Feb 17, 2011
Messages
3,970
Location
Hogwarts
Gender
Male
HSC
2012
Thanks...but why would it be "winning at least one prize"? If so, it implies that the event "winning all 2 prizes" is a subset of "winning one prize" as said in the question, which I think is a bit literally contradicting...
Some maths questions are really badly explained sometimes.
 

goobi

Member
Joined
Oct 6, 2010
Messages
196
Gender
Male
HSC
2012
Some maths questions are really badly explained sometimes.
I'm really afraid of the presence of this type of question in the HSC and the trial as I think I'm a bit disadvantaged for English being my second language...
 

powlmao

Banned
Joined
Feb 17, 2011
Messages
3,970
Location
Hogwarts
Gender
Male
HSC
2012
I'm really afraid of the presence of this type of question in the HSC and the trial as I think I'm a bit disadvantaged for English being my second language...
I believe most questions are really easy to understand. I have seen past HSC papers and all the questions are quite simple.


What does the answer say is the correct one?
 

goobi

Member
Joined
Oct 6, 2010
Messages
196
Gender
Male
HSC
2012
The suggested answer is found by "1 - P(winning no prize)", so the solution assumes that "winning a prize" implies "winning at least one prize".
 

kooliskool

Member
Joined
Nov 23, 2006
Messages
138
Gender
Male
HSC
2007
I can understand how you feel, if the hsc question is vague, it's hard to answer what they want if you don't understand the question. But keep this in mind, there are a board of people whose job is to design the paper so that no matter how you read it, there is only one meaning out of it. Whereas the textbook only has a few or sometimes only one person, so don't worry.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top