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probability question

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by robk100 » Fri Dec 14, 2007 3:31 pm
Hi for some reason i'm having trouble comprehending this.

I want to roll one dice. The first roll must be an even number. The second roll must be the number 4. I know the chances of doing this is 1/12, but what's the chances if the order doesn't matter. Ie. whether i roll a 4 or even number first doesn't matter as long as the second roll completes it. Please explain the answer and why.

Thanks in advance
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Source: — Problem Solving |

Re: probability question

by gabriel » Sun Dec 16, 2007 12:23 pm
robk100 wrote:Hi for some reason i'm having trouble comprehending this.

I want to roll one dice. The first roll must be an even number. The second roll must be the number 4. I know the chances of doing this is 1/12, but what's the chances if the order doesn't matter. Ie. whether i roll a 4 or even number first doesn't matter as long as the second roll completes it. Please explain the answer and why.

Thanks in advance
When the order doesnt mater there are two ways this event could happen, first you get a 4 and then you get a even number OR first u get a even number and then you get a 4, the probability of each of them happening is 1/12 so the total probability = 1/12+1/12 = 1/6 ..

Regards.
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thank you

by robk100 » Sun Dec 16, 2007 4:00 pm
Thank you for your reply I understand it now....
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