Probability of Rolling Sum > 3 with Two Dice

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Discussion Overview

The discussion revolves around calculating the probability of rolling a sum greater than 3 when two fair dice are rolled. It includes considerations of possible outcomes and methods for determining the probability.

Discussion Character

  • Mathematical reasoning
  • Technical explanation

Main Points Raised

  • One participant asks for the probability of rolling a sum that exceeds 3.
  • Another participant suggests that the probability might be 1/36.
  • A clarification is made that a sum exceeding 3 is equivalent to a sum greater than or equal to 4.
  • A detailed enumeration of all possible sums from rolling two dice is provided, noting that there are 36 total outcomes.
  • A question is raised about how many outcomes yield a sum of 4 or higher, indicating that this number will be used to calculate the probability.
  • One participant proposes an alternative method of counting the outcomes that result in sums of 2 or 3 and subtracting that from the total outcomes.

Areas of Agreement / Disagreement

Participants have not reached a consensus on the probability value, and multiple approaches to the problem are presented, indicating ongoing discussion and exploration of the topic.

Contextual Notes

The discussion does not resolve the exact number of outcomes that exceed a sum of 3, nor does it clarify the implications of the proposed methods for calculating the probability.

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Two fair dice are rolled. What is the probability of rolling a sum that exceeds 3?
 
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skeeter said:
main-qimg-959c62dd441929b7a0079f1cc2ef185a
is it 1/36
 
a sum that exceeds 3 is a sum $\ge$ 4
 
When rolling two dice the possible sums are 1+ 1= 2 to 6+ 6= 12. The specific possible outcomes are
1+ 1= 2
1+ 2= 3
1+ 3= 4
1+ 4= 5
1+ 5= 6
1+ 6= 7
2+ 1= 3
2+ 2= 4
2+ 3= 5
2+ 4= 6
2+ 5= 7
2+ 6= 8
3+ 1= 4
3+ 2= 5
3+ 3= 6
3+ 4= 7
3+ 5= 8
3+ 6= 9
4+ 1= 5
4+ 2= 6
4+ 3= 7
4+ 4= 8
4+ 5= 9
4+ 6= 10
5+ 1= 6
5+ 2= 7
5+ 3= 8
5+ 4= 9
5+ 5= 10
5+ 6= 11
6+ 1= 7
6+ 2= 8
6+ 3= 9
6+ 4= 10
6+ 5= 11
6+ 6= 12

A total of 6x6= 36 outcomes, not all different.

Now, how many of those "exceed 3" (i.e. are 4 or higher)? The probability of exceeding 3 is that number divided by 36.
 
You might find it simpler to count the number of rolls that give "2" or "3" and subtract that from 36.
 

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