Multiple choice

What is the chance of throwing at least $7$ in a single cast with $2$ dice?

  1. $\dfrac{5}{12}$
  2. $\dfrac{7}{12}$
  3. $\dfrac{1}{4}$
  4. $\dfrac{17}{36}$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Total outcomes = 36. Sum < 7: (1,1), (1,2), (1,3), (1,4), (1,5), (2,1), (2,2), (2,3), (2,4), (3,1), (3,2), (3,3), (4,1), (4,2), (5,1) = 15 outcomes. Sum >= 7 = 36 - 15 = 21. Probability = 21 / 36 = 7 / 12.

AI explanation

When two dice are cast, the total number of possible outcomes is 36. It is simpler to use the complementary probability by first finding the probability of scoring a 6 or less. The combinations that result in a sum of 6 or less are 15 out of the 36 outcomes, so the probability of getting at least a 7 is 1 minus 15/36. This equals 21/36, which simplifies to 7/12.

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