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A bag contains 6 red marbles, 7 blue marbles and 8 green marbles. If three marbles are drawn out of the bag, what is the exact probability that all three marbles drawn will be blue?
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A bag contains 66 red marbles, 77 blue marbles and 88 green marbles. If three marbles are drawn out of the bag, what is the exact probability that all three marbles drawn will be blue?\newlineAnswer:

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Q. A bag contains 66 red marbles, 77 blue marbles and 88 green marbles. If three marbles are drawn out of the bag, what is the exact probability that all three marbles drawn will be blue?\newlineAnswer:
  1. Determine total number of marbles: Determine the total number of marbles in the bag.\newlineThe bag contains 66 red marbles, 77 blue marbles, and 88 green marbles. So, the total number of marbles is 6+7+86 + 7 + 8.
  2. Calculate total number of marbles: Calculate the total number of marbles.\newline66 red + 77 blue + 88 green = 2121 total marbles.
  3. Determine probability of drawing one blue marble: Determine the probability of drawing one blue marble.\newlineThe probability of drawing one blue marble is the number of blue marbles divided by the total number of marbles, which is 721\frac{7}{21}.
  4. Determine probability of drawing a second blue marble: Determine the probability of drawing a second blue marble after one has already been drawn.\newlineAfter drawing one blue marble, there are now 66 blue marbles left and 2020 total marbles. The probability of drawing a second blue marble is now 620\frac{6}{20}.
  5. Determine probability of drawing a third blue marble: Determine the probability of drawing a third blue marble after two have already been drawn.\newlineAfter drawing two blue marbles, there are now 55 blue marbles left and 1919 total marbles. The probability of drawing a third blue marble is now 519\frac{5}{19}.
  6. Calculate probability of drawing three blue marbles in a row: Calculate the probability of drawing three blue marbles in a row.\newlineThe probability of drawing three blue marbles consecutively is the product of the probabilities of each draw:\newline(721)×(620)×(519)(\frac{7}{21}) \times (\frac{6}{20}) \times (\frac{5}{19}).
  7. Simplify the probability: Simplify the probability.\newline(721)×(620)×(519)=(13)×(310)×(519)=(1×3×53×10×19)=5190=138(\frac{7}{21}) \times (\frac{6}{20}) \times (\frac{5}{19}) = (\frac{1}{3}) \times (\frac{3}{10}) \times (\frac{5}{19}) = (\frac{1\times3\times5}{3\times10\times19}) = \frac{5}{190} = \frac{1}{38}.

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