SJ wrote:
A jar contains 4 marbles: 2 red and 2 white. 2 marbles are chosen at random.
Quantity A |
Quantity B |
The probability that the marbles chosen are the same colour |
The probability that the marbles chosen are different colours. |
Here's a quick approach.
First pick 1 marble, ANY marble. For this first step, picking either color is equally likely.
At this point, there are
3 marbles remaining in the jar.
1 marble is the SAME color as the first marble you selected, and
2 marbles are a DIFFERENT color from the first marble you selected.
So, it's more likely that the two marbles will be DIFFERENT colors
Answer:
Mathematically, P(matching colors) =
1/
3 and P(different colors) =
2/
3
_________________
Brent Hanneson – Creator of greenlighttestprep.com
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