A jar contains jelly beans. There are

6
6 red jelly beans,
4
4 blue jelly beans and
6
6 green jelly beans. You randomly take two jelly beans out to eat. What is the probability that one jelly bean is red and the other jelly bean is green? Write your answer as a fraction. You do not need to simplify. Click Here for Help Video

1 answer

To find the probability that one jelly bean is red and the other jelly bean is green, we can use the following steps:

  1. Total Jelly Beans Calculation:

    • Red jelly beans: 6
    • Blue jelly beans: 4
    • Green jelly beans: 6
    • Total jelly beans = 6 + 4 + 6 = 16
  2. Total Ways to Choose 2 Jelly Beans: The total number of ways to choose 2 jelly beans from 16 can be calculated using the combination formula \(\binom{n}{r}\), which is defined as \(\frac{n!}{r!(n - r)!}\).

    \[ \text{Total ways to choose 2 jelly beans} = \binom{16}{2} = \frac{16 \times 15}{2 \times 1} = 120 \]

  3. Ways to Choose 1 Red and 1 Green Jelly Bean:

    • The number of ways to choose 1 red jelly bean from 6: \(\binom{6}{1} = 6\)
    • The number of ways to choose 1 green jelly bean from 6: \(\binom{6}{1} = 6\)

    Therefore, the number of ways to choose 1 red and 1 green jelly bean is: \[ \text{Ways to choose 1 red and 1 green} = 6 \times 6 = 36 \]

  4. Probability Calculation: The probability that one jelly bean is red and the other is green is given by the ratio of the number of favorable outcomes (choosing 1 red and 1 green) to the total outcomes (choosing any 2 jelly beans):

    \[ P(\text{1 red and 1 green}) = \frac{\text{Ways to choose 1 red and 1 green}}{\text{Total ways to choose 2 jelly beans}} = \frac{36}{120} \]

Thus, the probability that one jelly bean is red and the other jelly bean is green is:

\[ \frac{36}{120} \]

You do not need to simplify it as per your request, so the final answer is:

\[ \frac{36}{120} \]