Give that two six sided dice are rolled once

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In summary, the odds against rolling a sum that is a multiple of 3 are 2 to 1. This is because there are twice as many ways to not roll a multiple of 3 as there are ways to roll a multiple of 3, with a total of 12 out of 36 combinations giving a multiple of 3. The probability against rolling a multiple of 3 is 2/3 or 24/36, which can be simplified to 2:3.
  • #1
SeththeBaller
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1. Given that two six sided dice are rolled once, what are the odds against rolling a sum that is a multiple of 3



3. The answer I got was 2:3

Was just wondering if this is correct.
 
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  • #2
Show your work.
 
  • #3
The highest possible number with a single roll of two dice is 12. Multiples of three going up to 12 are 3,6,9, and 12. Looking at the grid, there are 12 out of 36 combinations that give a sum that is a multiple of three ((1,2), (1,5), (2,1), (2,4), (3,3), (3,6), (4,2), (4,5), (5,1), (5,4), (6, 3),(6,6)). This means that the probability against rolling a sum that is a multiple of three is 24/36 because 36-12=24.

24/36 can be simplified to 2/3 , thus, the odds against rolling a sum that is a multiple of 3 is 2:3.
 
  • #4
Your calculation of the probability is fine. However, the odds would be 2 to 1 because there are twice as many ways to not roll a multiple of 3 as there are ways to roll a multiple of 3. The odds is the ratio of the relative probabilities of an event and its complement, so in this case you have (2/3) to (1/3) or 2 to 1.
 
  • #5
Thank you!
 

FAQ: Give that two six sided dice are rolled once

What is the probability of getting a sum of 7 when rolling two six-sided dice?

The probability of getting a sum of 7 when rolling two six-sided dice is 1/6 or approximately 16.67%. This is because there are six possible ways to get a sum of 7: (1,6), (2,5), (3,4), (4,3), (5,2), (6,1). Out of the total 36 possible outcomes, 6 of them result in a sum of 7.

What is the probability of getting a sum of 2 or 12 when rolling two six-sided dice?

The probability of getting a sum of 2 or 12 when rolling two six-sided dice is 1/36 or approximately 2.78%. This is because there is only one way to get a sum of 2: (1,1) and one way to get a sum of 12: (6,6). Out of the total 36 possible outcomes, only 2 of them result in a sum of 2 or 12.

What is the probability of getting a sum greater than or equal to 11 when rolling two six-sided dice?

The probability of getting a sum greater than or equal to 11 when rolling two six-sided dice is 1/12 or approximately 8.33%. This is because there are only two ways to get a sum of 11: (5,6) and (6,5). Out of the total 36 possible outcomes, only 3 of them result in a sum greater than or equal to 11.

What is the expected value of the sum when rolling two six-sided dice?

The expected value of the sum when rolling two six-sided dice is 7. This is because the average of all possible outcomes is 7. Out of the total 36 possible outcomes, there are 6 ways to get a sum of 7, 5 ways to get a sum of 8, 4 ways to get a sum of 9, and so on. When we add up all the possible sums and divide by 36, we get an average of 7.

What is the probability of getting a sum of 8 or less when rolling two six-sided dice?

The probability of getting a sum of 8 or less when rolling two six-sided dice is 5/12 or approximately 41.67%. This is because there are 5 ways to get a sum of 8 or less: (1,1), (1,2), (2,1), (2,2), (3,1). Out of the total 36 possible outcomes, 15 of them result in a sum of 8 or less.

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