SOLUTION: Hello, so if i have 9 red socks and 4 blue socks in a drawer, and i draw a sock twice without replacement, what is the probability that i have a pair?

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Question 593649: Hello, so if i have 9 red socks and 4 blue socks in a drawer, and i draw a sock twice without replacement, what is the probability that i have a pair?

Answer by Edwin McCravy(20054) About Me  (Show Source):
You can put this solution on YOUR website!


Use the principle that "AND" goes with "multiply" and 
"OR" goes with ADDITION:

 +  =

9%2F13·8%2F12 + 4%2F13·3%2F12 =

9%2F13·2%2F3 + 4%2F13·1%2F4 =

18%2F39 + 1%2F13 =

6%2F13 + 1%2F13 =

7%2F13

Edwin