Answer:
3/10
Explanation:
It is exactly as Mrscomputator said, but you have to multiply by 3
What Mrscomputator said, "To find the probability of two jellybeans being red, you will find the probability of getting a red jellybean in two of the three trials. Remember that in one trial, you will need a probability of not getting red.
1 - 4/10 (getting a red)
2 - 3/9 (getting a red)
3 - 6/8 (not getting a red)
If you change the order, the answer will be the same.
1 - 6/10 (not getting a red)
2 - 4/9 (getting a red)
3 - 3/8 (getting a red)
Multiply these together to get the probability.
4/10 x 3/9 x 6/8 = 1/10
The probability is 1/10."
You have cases like:
RRW
RWR
WRR
W is anything but red. So because there is 3 cases, it is what Mrscomputator said times 3. So the answer is 1/10 * 3 = 3/10.
You can also do this:
First, we consider how many total sets of three jellybeans we can select, which is very simply 10 choose 3= 120, if we treat all 10 jellybeans as distinct. Now, if we have exactly 2 red jellybeans, there are 4 choose 2 = 6 pairs of red jellybeans, and 5+1 = 6 choices for the third non-red jellybean. So, there are 6 times 6 = 36 successful outcomes. So our probability is 6 * 6 / 120 = 6 / 20 = 3 / 10.
Hope this helped! :)