What is the probability of rolling a sum greater than 10 and a sum of 10 when rolling two number cubes?

1 answer

To calculate the probabilities of rolling a sum greater than 10 and a sum of 10 with two number cubes (also known as dice), we need to examine the possible outcomes when rolling the dice.

  1. Total Outcomes: When rolling two six-sided dice, the total number of outcomes is \(6 \times 6 = 36\).

  2. Sum of 10: We need to count the pairs of rolls that give a sum of 10:

    • Possible combinations:
      • (4, 6)
      • (5, 5)
      • (6, 4)

    The pairs that sum to 10 are:

    • (4, 6)
    • (5, 5)
    • (6, 4)

    Thus, there are 3 combinations that result in a sum of 10.

  3. Sum Greater than 10: Now we determine the combinations that give sums greater than 10:

    • Possible sums greater than 10 are 11 and 12.

    • For sum of 11:

      • (5, 6)
      • (6, 5)
    • For sum of 12:

      • (6, 6)

    Thus, there are 3 combinations that result in sums greater than 10.

  4. Calculating Probabilities:

    • Probability of rolling a sum of 10: \[ P(\text{Sum of } 10) = \frac{\text{Number of ways to get 10}}{\text{Total outcomes}} = \frac{3}{36} = \frac{1}{12} \]

    • Probability of rolling a sum greater than 10: \[ P(\text{Sum greater than } 10) = \frac{\text{Number of ways to get greater than 10}}{\text{Total outcomes}} = \frac{3}{36} = \frac{1}{12} \]

So, the final probabilities are:

  • The probability of rolling a sum of 10 is \(\frac{1}{12}\).
  • The probability of rolling a sum greater than 10 is also \(\frac{1}{12}\).