Question

I really need help!!!!

A bag contains 8 red marbles, 5 blue marbles, 4 green marbles, and 7 yellow marbles. Five marbles are randomly drawn from the bag one at a time and not replaced. What is the probability that the first three marbles drawn are red?

Answer 1

Explanation:

The colour of the ‘non-green’ marbles is immaterial so the question comes down to the probability of not drawing any green marbles from a bag containing 5 green marbles and 12 (8+4) non-green marbles.

This can be re-worded as the probability of randomly drawing 4 non-green marbles from a bag initially containing 17 (12+5) marbles.

The probability of the first being non-green is 12/17.

For the second the number of non-green marbles reduces, as does the total number of marbles giving a probability of 11/16

For the third (similar) 10/15For the fourth 9/14

The probability of making these 4 successive picks is the product of the individual probabilities = 12/17 * 11/16 * 10/15 * 9/14 = 11880/57120 = 99/476 = 20.8% (approx.)

Answer 2

Answer: 0.0277

Step-by-step explanation: 8 red marbles and 24 total

(8/24)(7/23)(6/22)=7/253=0.0277