There is a bag filled with 5 blue, 6 red and 2 green marbles. A marble is taken at random from the bag, the colour is noted and then it is not replaced.
Another marble is taken at random.
What is the probability of getting 2 the same colour?

Step-by-step explanation:

Let's separate into 3 cases:

Note that we put the number of color balls we want in the numerator and the total number of color balls remaining in the denominator.

Case 1: 2 blue marbles

(There were 5 blues originally, and 4 blues after 1 blue is taken out, same logic but different colors and values in case 2 and 3.)

Case 2: 2 red marbles

Case 3: 2 green marbles

Now add up all 3 cases and you will have the probability as required.

1. 2

2. 11

3. 5

4. 6

5. 7

6. 5

7. -1

8. 1

step-by-step explanation:

can i know which language is this?