Sunday, April 19, 2009

SAT question?

In a certain flower shop, only 3 vases of flowers and 1 wreth can be displayed om the front of the window at one time. If there are 10 vases of flowers and 4 wreaths to choose from, how many different arrangements of vases and wreaths are possilbe?





THANKS
SAT question?
Say
FlowersBirthday FlowersSympathy FlowersYou multiply all possible options.





10 * 9 * 8 * 4 = 2880





It goes 10 9 8 for vases because after you pick one out of 10, you have 9 left, then 8, etc... And you only choose one wreath so you just multiply by 4.
Reply:Order is not important, so we will use combination





10C3 + 4C1 = 124 different arrangements of vases and wreaths
Reply:This is a combinatorics question. The answer is:





( 10) = (10*9*8*7*6*5*4*3*2*1)/ (3*2*1)*(7*6*5*4*3*2*1)


( 3)


= 120 Vase arrangements








( 4) = (4*3*2*1)/(3*2*1) = 4 Wreath Arrangements


( 1)





4 Wreath Arrangements * 120 Vase arrangements =


480 possible arrangements
Reply:(the number of combinations of 10 things taken three at a time) multiplied by (the number of combinations of 4 things taken one at a time)





(10! / ( (10-3)! * 3!) ) * ( 4! / ((4-1)! * 1!))





10! / ( 7! * 3! ) * 4





(10*9*8 / 3*2*1 ) * 4





720 / 6 * 4





480








That is if you don%26#039;t care about the order in which they are displayed. If you care about the order, then it%26#039;s 10*9*8*4 = 2880.
Reply:3 out of 10 vases:


10*9*8=720 if the order matters or 10*9*8/1*2*3=120 if the order doesn%26#039;t matter.


1 out of 4 wreaths: 4 choices.


if the order doeasnt matter, 120*4=480 possibilities.


if the order matters but the wreath can only be in 1 place:


720*4=2880 possibilities
Reply:There are 10C3 = 10*9*8/3! = 120 combinations of vases and 4 wreath combinations. For a total number of cominations of:





4*120 = 480nanny

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