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How many ways can nico display 7 medals in a row? (A) 7 (B) 14 (C) 21 (D) 5040

User Nachshon F
by
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1 Answer

7 votes

Answer: 5040

Step-by-step explanation

Nico has 7 choices for the 1st slot, then 6 choices for the 2nd slot, 5 choices for the 3rd slot, and so on. We count down to 1 multiplying along the way.

7*6*5*4*3*2*1 = 5040

For more information, search out "factorials".

Many calculators have a built-in factorial feature. It is indicated by an exclamation mark. So if you were to type in "7!", without quotes, then it would produce the answer 5040. This assumes that your calculator has the factorial feature.

Another route would be to use the nPr permutation formula. Plug in n = 7 and r = 7.

The nPr permutation formula is:


_nP_r = (n!)/((n-r)!)

User Rich Linnell
by
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