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Riddle time

Posted: October 4, 2004, 3:04 pm
by Dups.
Cat = 50 cents
Dog = 3 dollars
Horse = 10 dollars

You need to purchase 100 animals. You need to have at least one of each (so at least 1 cat , dog and horse). The total amount for these 100 animals needs to equal 100 dollars.


Use a spoiler tag if you think you have the answer. As to not spoil it for others please.

Posted: October 4, 2004, 3:12 pm
by Neost
How about:
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nevermind, i re-read and i missed the requirement for 100 animals.

Posted: October 4, 2004, 3:21 pm
by archeiron
There are two equations and loose limitations, so there are many solutions:
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94 cats ($47), 1 dog ($3), and 5 horses ($50) is 100 animals ($100)

Ah, yeah, there is only one solution with positive integer values. I doubt that someone would sell part of a horse or negative number of cats. ;)

Posted: October 4, 2004, 3:32 pm
by Llaffer
Solved with a c program:
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94 cats; 1 dog; 5 horses
I tried to use algebra, but with 2 formulas and 3 variables, couldn't be solved. If there is a 3rd formula in that, I've failed to see it.

Posted: October 4, 2004, 4:07 pm
by archeiron
Llaffer wrote:Solved with a c program:
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94 cats; 1 dog; 5 horses
I tried to use algebra, but with 2 formulas and 3 variables, couldn't be solved. If there is a 3rd formula in that, I've failed to see it.
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x = no. of cats
y = no. of dogs
z = no. of horses

given:

0.5x + 3y + 10z = 100
x + y + z = 100

therefore x = 100 - y - z

thus
0.5(100- y - z) + 3y + 10z = 100
or

y = 20 - (19/5)z

We want the value of all three numbers to be positive integers, so z should be 0, 5, 10, 15.... We also know that all three be greater than 1.

Therefore,

z=5

(if z=10 or greater, then y is negative. If z is not a multiple of 5, then y is not a whole number. All numbers must be greater than 1.)

if z=5, then y=1 and x=94.

Posted: October 4, 2004, 4:12 pm
by Ogbar
Solved by Algebra, more or less as archeiron did it.

Posted: October 4, 2004, 4:29 pm
by Winnow
Got the answer by looking at a spoiler.

Posted: October 5, 2004, 9:08 am
by Ajran
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94 cats = 47, 1 dog = 3 5 horses = 50, 94+1+5= 100 47+3+50=100

Posted: October 5, 2004, 4:32 pm
by Cracc
I just realized that:

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Winnow is gay!

Posted: October 5, 2004, 5:53 pm
by Winnow
Cracc wrote:I just realized that:

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Winnow is gay!
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My bad! I thought you were a woman!

Posted: October 5, 2004, 6:25 pm
by Rivera Bladestrike
Winnow wrote:
Cracc wrote:I just realized that:

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Winnow is gay!
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My bad! I thought you were a woman!
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Well with a Hello Kitty as his avatar, who could blame you!

Posted: October 5, 2004, 6:41 pm
by *~*stragi*~*
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I approve of posting everything from now until ever, under the spoiler tag.