REMEMBER....

Permutations

Arranging items when order matters

AB is different than BA


nPr
 

 the number of ways "n" things can be arranged in groups of size "r" (order matters)

6P4= n(n-1)(n-2)...
"r" times

 


In how many different ways can 5 students be arranged in a row of 5 chairs?
A. 60
B. 25
C. 15
D. 120
 

 


 


How many 3 letter words (spelling not important) can be formed from the letters in the word "STEAM" if each letter is used only once in each word?
 


A. 120
B. 60
C. 12
D. 24






 


How many different 3 person committees can be formed from a group of 16 people?
 

  
A. 48
B. 45
C. 3360
D. 4590




Joe has 6 school books, but only room on his bookshelf at home for 4 of them.  how many different 4 book groupings are possible?
 

A. 360
B. 120
C. 720
D. 180
 




 

 


If, in a horse race, there are 3 winning positions (win, place and show), how many possible winning orders would there be in a race with 12 horses?
 
A. 132
B. 1320
C. 880
D. 33
 

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