Need help on Probability Question! (1 Viewer)

Coookies

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Abdallah buys 4 tickets in a raffle in which 100 tickets are sold altogether. There are 2 prizes in the raffle. Find the probability that Abdallah will win
c) one prize


Thanks!
 
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bladeys

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c) 4/100 x 96/99 x 2

d) 96/100 x 95/99

e) 1 - [96/100 x 95/99]
 

nightweaver066

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c) P(one prize) = 4/100 x 96/99 + 96/100 x 4/99 = 64/825
Found by considering the two cases where he wins one and doesn't win the other and vice versa
d) P(no prizes) = 96/100 x 95/99 = 152/165
Multiplying his probability of not drawing his tickets from first and second draw
e) P(at least one prize) = 1 - P(no prizes) = 13/165
 

Coookies

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I have another question

Mary buys 20 tickets in a lottery that has 5000 tickets altogether. Find the probability that Mary will win
b) 2nd prize only
c) neither first nor second prize

I know this is similar to the first question but I'm getting scientific notations and decimal points...
 

nightweaver066

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I have another question

Mary buys 20 tickets in a lottery that has 5000 tickets altogether. Find the probability that Mary will win
b) 2nd prize only
c) neither first nor second prize

I know this is similar to the first question but I'm getting scientific notations and decimal points...
Is there only 1st and 2nd prize?
 

nightweaver066

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I have another question

Mary buys 20 tickets in a lottery that has 5000 tickets altogether. Find the probability that Mary will win
b) 2nd prize only
c) neither first nor second prize

I know this is similar to the first question but I'm getting scientific notations and decimal points...
b) P(2nd prize only) = 4980/5000 x 20/4999
Multiply probability of not winning anything on first draw but winning on second

c) P(neither first nor second prize) = 4980/5000 x 4979/4999
Multiply probability of not winning anything on first and second draw
 

Coookies

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I make such silly mistakes...

but for c) I got 0.992015203 but the book says 1239771/1249750

Oh wait, its the same, but my calculator isn't letting me convert from decimal to fraction
 

Carrotsticks

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Press this button on the calculator when it is in fraction form:

 

nightweaver066

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I make such silly mistakes...

but for c) I got 0.992015203 but the book says 1239771/1249750

Oh wait, its the same, but my calculator isn't letting me convert from decimal to fraction
Silly question seeing as you can't get the fraction form in your calculator..

For probability, take your time and think about the question carefully.

Consider what you need to find, and take it step by step.

Keep practising questions!
 

Coookies

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I did but its not working, number is too big perhaps?
 

Coookies

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Lol you guys probably think I have some old shitty calculator. I have the newest one and it converts for everything else, but this number
 

Coookies

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Im going to have quite a few questions tonight lol, trying to get through this exercise

Q. If 4 dice are thrown, find the prob. that the dice will have
b) only one 6
 

Carrotsticks

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Im going to have quite a few questions tonight lol, trying to get through this exercise

Q. If 4 dice are thrown, find the prob. that the dice will have
b) only one 6
One die is 6 = 1/6

Other three die can NOT be 6, so = 5/6

But there are 4 die that can get a 6, so 4

Thus, answer is 1/6 x 5/6 x 4 = 5/9
 

SpiralFlex

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What is the probability of me losing weight (10 kg) in a few weeks?
 

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