A single die is rolled 3 times. Find the probability of rolling one 1 times. State answer as a decimal rounded to six decimal places.
Real Tutor Solution
Answer
Solution
Reviewed and approved by the UpStudy tutoring team
Bonus Knowledge
To find the probability of rolling one '1' in three rolls of a die, we can use the binomial probability formula. The probability of rolling a '1' on a six-sided die is \( \frac{1}{6} \), and the probability of not rolling a '1' is \( \frac{5}{6} \). The possible scenarios where exactly one '1' is rolled in three rolls can be represented as: - Rolling a '1' on the first roll and not on the others: \( \frac{1}{6} \cdot \left(\frac{5}{6}\right)^2 \) - Rolling a '1' on the second roll: \( \left(\frac{5}{6}\right) \cdot \frac{1}{6} \cdot \left(\frac{5}{6}\right) \) - Rolling a '1' on the third roll: \( \left(\frac{5}{6}\right)^2 \cdot \frac{1}{6} \) The total number of combinations in which one can achieve this is given by \( \binom{3}{1} = 3 \). Therefore, we calculate: \[ P(X = 1) = \binom{3}{1} \left(\frac{1}{6}\right)^1 \left(\frac{5}{6}\right)^2 = 3 \cdot \frac{1}{6} \cdot \left(\frac{25}{36}\right) = 3 \cdot \frac{25}{216} = \frac{75}{216} \approx 0.347222 \] Rounded to six decimal places, the probability of rolling a '1' exactly one time when rolling a die three times is approximately **0.347222**.