Question

​Find the probability that first marble picked is green and second marble picked is red.

​Write your result as a percentage.


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Answer 1

20%

Explanation:

3 green, 1 brown, 2 red

3 + 1 + 2 = 6

Total: 6

The probability of picking a green one is 3/6 or 1/2.

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2 green, 1 brown, 2 red

2 + 1 + 2 = 5

New total: 5

The probability of picking a red one is now 2/5.

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First, we multiply them by each other.

2/5 x 1/2 = 1/5

Next, we convert 1/5 to a percentage to get our final answer.

1/5 x 20 = 20/100, which is 20%.

So our final answer is 20%.

Answer 2

Since there’s 6 marbles and there’s 3 greens and 2 reds, we’re finding P(A and B). Where P(A) is first marble picked is green, and P(B) is second marble picked is red.

P(A) = 3/6

(Because the first marble as already been picked there’s 5 marbles left) so:

P(B) = 2/5

Now we have to find the probability of A and B

P(A and B) = 3/6 • 2/5 = 1/5 = 20%