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#1 2007-05-05 20:23:36

Alizah
Guest

Probability - what's the method?

Could someone please check this for me :-). Thank-you

A box contains 22 red apples and 3 green apples. Three apples are selected at random one after the other without replacement.

What is the probability that exactly two of the three apples are red?

The way I'm trying to solve the problem is like this:
Possible combinations:
RRG
GRR
RGR

probability of red: 3/25
probability of green: 22/25

3/25 * 2/24 * 22/23 = 11/1150
22/25 * 3/24 * 2/23 = 11/1150
3/25 * 22/24 * 2/23 = 11/1150

So the answer would be (11/1150)*3 = 33/1150

Is this correct?

#2 2007-05-05 20:42:21

Alizah
Guest

Re: Probability - what's the method?

Nevermind!!

I just found out I switched around the probabilities for red and green apples, lol

thanks anyway:D

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