7. A bag contains 5 red marbles, 6 green marbles, and 9 blue marbles. Suppose 3 marbles are chosen without replacement. What is the probability of choosing a red, a blue, and a red in that order?:


A. 9/320

B. 5/152

C. 1/1280

D. 1/38

This answer was scored wrong, but I do not know why. If someone would kindly show me the error, I would appreciate it.

First choice probability: 5/20
Second choice probability: 6/19
Third choice probability: 9/18

Total Probability: (5/20)(5/19(9/18)=3/76

This answer is not featured above but the math seems correct. Each successive choice has fewer balls remaining, and the correct number of the desired balls for the next choice still remains in the bag for all the choices. The total probability is the product of the probability of each choice.

(¡) 5/17

the answer is B. when you multiply you get (225/6840) simplifing this and you will get 5/152.

A cup contains 9 red jelly beans, 8 green jelly beans, and 8 blue jelly beans.

If a jelly bean is randomly chosen, what is the probability that it is not green? Write your answer as a simplified fraction.

17/25

the answer Red then blue the red is D.

1 of 38 or 2.63% chance
5 red chances /20 balls *
9 blue /19 * 4 red balls left /18
= .25 X .47368 * .2222 = .0263
or 1/38

A bucket contains 5 yellow and 7 red balls. If 2 balls are selected randomly without replacement, what is the probability that they will both be yellow?

5/20*9/19*4/18 = 1/4*9/19*2/9 =

1/2*1/19 = 1/38

To find the probability of choosing a red, a blue, and a red in that order, we need to consider the number of favorable outcomes and the number of possible outcomes.

First, let's calculate the number of favorable outcomes. We need to choose one red marble, one blue marble, and another red marble in that order. There are 5 red marbles to choose from for the first choice, 9 blue marbles for the second choice, and 4 red marbles for the third choice (since one red marble has already been chosen). Therefore, the number of favorable outcomes is:

5 * 9 * 4 = 180

Next, let's calculate the number of possible outcomes. We are choosing 3 marbles without replacement from a total of 5 red marbles, 6 green marbles, and 9 blue marbles. So, the total number of marbles to choose from is 5 + 6 + 9 = 20. Therefore, the number of possible outcomes is:

20 choose 3 = (20 * 19 * 18) / (3 * 2 * 1) = 1140

Now, let's calculate the probability. The probability is given by the formula: probability = favorable outcomes / possible outcomes. Plugging in the values, we have:

probability = 180 / 1140 = 1 / 6.33

To simplify the fraction, we can multiply both the numerator and denominator by 1000:

probability = (180 * 1000) / (1140 * 1000) = 180000 / 1140000 = 15 / 95

Now, to compare this probability to the given options, let's find the option that is equal to or closest to 15/95:

A. 9/320
B. 5/152
C. 1/1280
D. 1/38

Comparing the options, we find that D. 1/38 is the closest option to 15/95.

Therefore, the probability of choosing a red, a blue, and a red in that order is approximately 1/38.

The correct answer is D. 1/38.