A contractor wishes to build 9 houses, each different in design. In how many ways can he place the houses on a street if 6 lots are on one side of the street and 3 lots are on the opposite side?

Question

anonymous · Answer

Its combination i think...@lgbasallote

anonymous · Answer

Nope it is purmutation since it is about arrengement.

anonymous · Answer

he is  choosing a slot

anonymous · Answer

Do u have the answer @lgbasallote

anonymous · Answer

9!

anonymous · Answer

The fact you can have facing sides doesn't really make a difference...

lgbasallote · Answer

i don't @Yahoo!

anonymous · Answer

I think it is about cyclic purmutation
Thus the answer will be (n-1)! =8!

lgbasallote · Answer

it's cyclic?

anonymous · Answer

Cyclic means arranging in circular order.

anonymous · Answer

Why would it be cyclic?

anonymous · Answer

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anonymous · Answer

Which is the same as |dw:1349441806156:dw|

Isn't it?

anonymous · Answer

Which makes it a trivial question really...

anonymous · Answer

I don't agree why u put the lines together?

anonymous · Answer

Why not?

anonymous · Answer

U must have good reason to put them together.

anonymous · Answer

For the first house you have 9 choices, for the second one 8, for the third one 7 etc.
Comes down to 9*8*7*6*5*4*3*2*1 = 9!

anonymous · Answer

Here is my way, we can consider the road as the center of the circular arrangement so as to apply cyclic permutation.

anonymous · Answer

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anonymous · Answer

Which still gives me 9*8*7*6*5*4*3*2*1 choices

anonymous · Answer

It will not.
For cyclic permutation the formula is (n-1)!

anonymous · Answer

Slap me around with formulas all you want, i fail to see how 1. The question asks for cyclic permutations 2. (n-1) applies to my drawing...

anonymous · Answer

Besides, i outrank you 65 > 62 ;)

shubhamsrg · Answer

9C6 ?

shubhamsrg · Answer

= 84 ?

lgbasallote · Answer

is "place" a combination or permutation?

anonymous · Answer

Since the houses have no relations, it's permutation

shubhamsrg · Answer

i guess the order in which houses are kept dont matter,,i.e. if 3,7,8 are on one side,,then 3,7,8 ; 3,8,7 ; 8,7,3 etc are the same,,so i say combination..

shubhamsrg · Answer

ohh wait,,is question like this : 
9 houses are there,,6 on 1 side,,3 on other,,and how many different ways can be there to give them 9 different designs ?

shubhamsrg · Answer

do you have an answer ?

lgbasallote · Answer

i do not

shubhamsrg · Answer

hmm,,maybe i dont understand question quite clearly,,does permutations of designs matter  ?

lgbasallote · Answer

what do you mean permutation of design?

shubhamsrg · Answer

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