Question 621514
A farmer bought 100 animals for $100.00.  Pigs are $10, goats are $3, and chickens are $.50.  How many of each animal did he purchase.
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10p + 3g + c/2 = 100 (total cost)
p + g + c = 100 (total animals)
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There are 3 variables but only 2 equations.
The "trick" is, the variables have to be integers.
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c has to be an even number.
p has to be less than 10
From there, it's trial and error.
I've seen references to Diophantine Equations that might apply here, but I don't know about them.
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I'll work on this later.