Please help me with question 21! Twenty Points!

8/15

Step-by-step explanation:

Step 1:

Total number of pins for the first draw  = 10

Number of blue pins = 3

Number of green pins = 7

Probability of the first pin drawn is blue is 3/10

For the second draw, without replacement

Total sample space = 9

Number of blue pins = 2

Probability that the second pin drawn is also blue is 2/9 [because the pin is drawn without replacement]

So probability that both the pins drawn are blue is 3/10*2/9 = 6/90

Step 2 :

To find the Probability that both the pins drawn are green

Total sample space for the first draw  = 10

Number of green pins = 7

Probability of the first pin drawn is green is 7/10

For the second draw, without replacement

Total sample space = 9

Number of green pins = 6

Probability that the second pin drawn is also green is 6/9 [because the pin is drawn without replacement]

So probability that both the pins drawn are green is 7/10*6/9 = 42/90

Step 3:

Probability that both the pins drawn are of the same color, that is both are blue or both or green is

6/90 + 42/90 = 48/90 = 8/15