Q. If a fair die is rolled 3 times, what is the probability, to the nearest thousandth, of getting exactly 2 twos?Answer:
Determine total outcomes: Determine the total number of outcomes for rolling a die 3 times.Since a die has 6 sides, each roll has 6 possible outcomes. For 3 rolls, the total number of outcomes is 6×6×6.Total number of outcomes = 63=216.
Number of ways for 2 twos: Determine the number of ways to get exactly 2 twos in 3 rolls.We can get two twos in the following sequences: (2,2,not 2), (2,not 2,2), (not 2,2,2).For each sequence, there are 5 possibilities for the 'not 2' roll (since it can be any number from 1 to 6 except 2).Number of ways to get exactly 2 twos = 3 sequences 315 possibilities = 33.
Calculate probability: Calculate the probability of getting exactly 2 twos.Probability = Number of ways to get exactly 2 twos / Total number of outcomes.Probability = 21615.
Simplify and round: Simplify the probability and round to the nearest thousandth.Probability ≈21615≈0.0694444444.Rounded to the nearest thousandth, the probability is 0.069.
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