SOLUTION: From the 20 CD’s you bought this past year, you plan to take 4 with you on vacation. How many different sets of four CD’s can you take?

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Question 1202050: From the 20 CD’s you bought this past year, you plan to take 4 with you on vacation. How many different sets of four CD’s can you take?
Answer by greenestamps(13203) About Me  (Show Source):
You can put this solution on YOUR website!


Literally, "20 choose 4". The calculation for that is

%2820%2A19%2A18%2A17%29%2F%284%2A3%2A2%2A1%29

You can do the calculations. Or many calculators like the TI-83 and TI-84 have built-in functions for doing them.