There are 10 marbles in a jar. 4 black, 3 gold, 2 white and 1 rainbow colored.

Answer 1

There are a total of 10 marbles in the jar, with the following breakdown:

- 4 black marbles
- 3 gold marbles
- 2 white marbles
- 1 rainbow colored marble

Answer 2

What is the probability of pulling 2 black marbles in a row if the marbles are replaced after each pull?

Answer 3

If the marbles are replaced after each pull, the probability of pulling a black marble on the first try is 4/10 or 2/5. Since the marbles are replaced, the probability of pulling another black marble on the second try is also 4/10 or 2/5.

To find the probability of both events happening (pulling 2 black marbles in a row), we multiply the probabilities:

(2/5) * (2/5) = 4/25

Therefore, the probability of pulling 2 black marbles in a row if the marbles are replaced after each pull is 4/25 or 0.16 or 16%.

Answer 4

What is the probability of pulling 2 white marbles in a row if the marbles are not replaced after each pull?

Answer 5

If the marbles are not replaced after each pull, the probability of pulling a white marble on the first try is 2/10 or 1/5. Since the marbles are not replaced, there will be one less white marble in the jar for the second pull, making the probability of pulling a white marble on the second try 1/9.

To find the probability of both events happening (pulling 2 white marbles in a row), we multiply the probabilities:

(1/5) * (1/9) = 1/45

Therefore, the probability of pulling 2 white marbles in a row if the marbles are not replaced after each pull is 1/45 or approximately 0.0222 or 2.22%.