Find the probabilıtie that A bag contains 12 marbles, four of each of the colours red, white and blue.

A marble is removed, its colour noted, then returned to the bag. A second marble is then
chosen and its colour noted. Find the probability that the two marbles are not the same
colour
of events

5 answers

There are a total of 12 marbles in the bag, with 4 of each color (red, white, blue).

The total number of ways to choose two marbles from the bag is C(12, 2) = 66.

The number of ways to choose two marbles of different colors is equal to the number of ways to choose one marble of each color. This can be achieved in the following ways:
- Red & White: C(4, 1) * C(4, 1) = 16
- Red & Blue: C(4, 1) * C(4, 1) = 16
- White & Blue: C(4, 1) * C(4, 1) = 16

So, the total number of ways to choose two marbles of different colors is 16 + 16 + 16 = 48.

Therefore, the probability that the two marbles are not the same color is 48/66 = 24/33 = 8/11.
But the answer is 2/3 please do further research
Apologies for the mistake in my previous calculation. Let's reevaluate the probability.

We have already determined that there are C(12, 2) = 66 ways to choose 2 marbles from the bag.

Now, let's calculate the number of ways to choose two marbles of the same color:
- Red & Red: C(4, 2) = 6
- White & White: C(4, 2) = 6
- Blue & Blue: C(4, 2) = 6

So, the total number of ways to choose two marbles of the same color is 6 + 6 + 6 = 18.

The number of ways to choose two marbles that are not the same color is the total number of ways to choose two marbles minus the number of ways to choose two marbles of the same color, which is 66 - 18 = 48.

Therefore, the probability that the two marbles are not the same color is 48/66 = 8/11 = 0.7273 or approximately 72.73%.
That's still nit the answer the answer is 2 on 3
Let's try to solve it step by step.

Total number of marbles = 12

Number of marbles of each color = 4

Total number of ways to choose 2 marbles = C(12, 2) = 66

Number of ways to choose 2 marbles of the same color:
- Red & Red: C(4, 2) = 6
- White & White: C(4, 2) = 6
- Blue & Blue: C(4, 2) = 6

Total number of ways to choose 2 marbles of the same color = 6 + 6 + 6 = 18

Number of ways to choose 2 marbles of different colors = Total number of ways to choose 2 marbles - Number of ways to choose 2 marbles of the same color
= 66 - 18 = 48

Therefore, the probability that the two marbles are not the same color is 48/66 = 8/11 = 0.7273 or approximately 72.73%.

It seems that despite the previous corrections, the answer is still not coming out as 2/3. I will reevaluate the solution to see if there was any mistake in the calculation. Starting from the calculation of the total number of ways to choose 2 marbles and then determining the probability of choosing marbles of different colors. Thank you for your patience.