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So, I'm pretty sure that it's more likely that we roll a total 8 when 2 dice are used, but how do I calculate the probability of rolling a total of 8 when 3 dice are used? -Brandy | So, I'm pretty sure that it's more likely that we roll a total 8 when 2 dice are used, but how do I calculate the probability of rolling a total of 8 when 3 dice are used? -Brandy | ||
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| + | You're right. It is more likely to roll a total of 8 when 2 dice are used. To calculate the probability with 3 dice, you need to take all of the combinations of getting eight and then divide by 216 (which is 6^3). So for instance, 1+1+6 is one possibility (and there are 3 of these... 1+1+6, 1+6+1, 6+1+1). You do it in a similar fashion for the rest of the possible combinations, and then compare the probabilities. -Emily | ||
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| + | Does the order matter in this problem?? such that is 6 + 1 + 1 and 1+ 6 + 1 different? | ||
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| + | Order does matter in the sense that rolling a 6, a 1, and then another 1 is different from rolling a 1, a 6, and then another 1. --[[User:Kfox|-Kristen]] 19:26, 18 February 2009 (UTC) | ||
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| + | This can be done by looking at the individual die's average rolls. For 3 die, each die rolls a 8/3; and for 2 die it is 8/2. Next, by comparing these results with the average roll, 7/2, it is easy to see that an 8 would occur more often with 2 die. | ||
| + | -Chris Ruderschmidt | ||
Latest revision as of 20:02, 18 February 2009
So, I'm pretty sure that it's more likely that we roll a total 8 when 2 dice are used, but how do I calculate the probability of rolling a total of 8 when 3 dice are used? -Brandy
You're right. It is more likely to roll a total of 8 when 2 dice are used. To calculate the probability with 3 dice, you need to take all of the combinations of getting eight and then divide by 216 (which is 6^3). So for instance, 1+1+6 is one possibility (and there are 3 of these... 1+1+6, 1+6+1, 6+1+1). You do it in a similar fashion for the rest of the possible combinations, and then compare the probabilities. -Emily
Does the order matter in this problem?? such that is 6 + 1 + 1 and 1+ 6 + 1 different?
Order does matter in the sense that rolling a 6, a 1, and then another 1 is different from rolling a 1, a 6, and then another 1. ---Kristen 19:26, 18 February 2009 (UTC)
This can be done by looking at the individual die's average rolls. For 3 die, each die rolls a 8/3; and for 2 die it is 8/2. Next, by comparing these results with the average roll, 7/2, it is easy to see that an 8 would occur more often with 2 die. -Chris Ruderschmidt
