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COUNTING AND PROBABILITY - COMBINATIONS?

How many different ways can three CDs be chosen from a case of 10 CDs?

a.) 5,040b.) 210c.) 40d.) 151,200

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2 Answers

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  • 1 month ago
    Favorite Answer

    10! 

    over

    3! (10 - 3)!

    10 9 8 7 6 5 4 3 2 1

    --------------------------

    3 2 1 7 6 5 4 3 2 1

    all cancel except 10 9 8 over 3 2 1 = 720/6 = 120

  • 1 month ago

    The answer is that there are 10 options for the first, 9 for the second and 8 for the third.

    10*9*8   = 10!/7! = 10!/(10-3)!

    • Puzzling
      Lv 7
      1 month agoReport

      order is not important

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