SOLUTION: when young MacDonal was starting his farm a long time ago,cows cost $10 each,pigs cost $3 each and chickens cost $0.50 each. He puechsed at least one of kind of animal. He paid $10

Question 160102: when young MacDonal was starting his farm a long time ago,cows cost $10 each,pigs cost $3 each and chickens cost $0.50 each. He puechsed at least one of kind of animal. He paid $100 for exatly 100 animals. HOW MANY CHICKENS DID HE BUY?
Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!
If cows cost $10 each, pigs cost $3 each and chickens cost $0.50 each. He got at
least one of kind of animal. He paid $100 for exactly 100 animals.
HOW MANY CHICKENS DID HE BUY?
:
x = no. cows
y = no. pigs
z = no. of chickens
:
Total animal equation
x + y + z = 100
:
Total cost equation
10x + 3y + .5z = 100
:
Multiply the above equation by 2 and subtract the 1st equation (total animals)
20x + 6y + 1z = 200
x + y + 1z = 100
-----------------------subtraction eliminates z
19x + 5y = 100
Arrange equation in the general y= form
5y = 100 - 19x
y = 20 - x; divided both sides by 5
:
Study this equation and it's apparent the only value for x that will give a
positive integer value for y, is x = 5
:
y = 20 - *5
y = 20 - 19
y = 1 pig
:
We have 5 cows, 1 pig
Find chickens: 100 - 5 - 1 = 94 chickens
:
Check:
10(5) + 3(1) + 94(.5) =
50 + 3 + 47 = 100
RELATED QUESTIONS
When young MacDonald was starting his farm a long time ago, cows cost $10 each, pigs cost (answered by ptaylor)

Old Mcdonald was buying animals for his farm. Cows cost $10, Pigs cost $3, and chickens... (answered by ankor@dixie-net.com)

Cows cost $10, pigs cost $3 and chickens cost $0.50. A man buys 100 animals for $100. How (answered by ankor@dixie-net.com)

Cows cost $10, pigs cost $3 and chickens cost $0.50. A man buys 100 animals for $100. How (answered by josmiceli)

u buy 100 animals for $100, cows cost $10,pigs cost $1.75 and chickens cost $.50 how many (answered by ikleyn)

a famer has $100 doallrs to spend on 100 animals. he has to end up with 100 animals.... (answered by KMST)

Farmer Del has 40 more chickens than cows on his farm. He also has 10 fewer pigs than... (answered by ikleyn,MathTherapy)

if you have $100 and you have to buy 100 animals cows cost $10 pigs cost $5 and chickens... (answered by josmiceli)

The goal is to buy exactly 100 farm animals with exactly 100 dollars. You must buy at... (answered by richwmiller)