SOLUTION: there are 13 animals in the barn.some are chicken some are pigs. there are 40 legs in all. how many of each animal are there?

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Question 698414: there are 13 animals in the barn.some are chicken some are pigs. there are 40 legs in all. how many of each animal are there?
Found 2 solutions by Simnepi, htmentor:
Answer by Simnepi(216) (Show Source):
You can put this solution on YOUR website!
You have to make two equations and solve them together.
Let the number of chickens be called c and let the number of pigs be p.
there are 13 animals in the barn so
p + c = 13 this is equation 1.
Since pigs have 4 legs the number of legs that the pigs have altogether is 4p and similarly chickens only have 2 legs so the number of their legs will be 2c.
so 2c + 4p = 40 this is equation 2
using equation 1 we can see that c = 13 - p
putting this value into equation 2 and solving
2X(13-p) + 4p = 40
26-2p+4p = 40
2p = 14
p = 7 there are 7 pigs
hence there are 6 chickens

Answer by htmentor(1343) (Show Source):
You can put this solution on YOUR website!
Let c = the number of chickens
Let p = the number of pigs
The total number of animals is 13:
c + p = 13 -> p = 13 - c
There are 40 legs in all:
2c + 4p = 40
2c + 4(13-c) = 40
Solve for c:
2c + 52 - 4c = 40
2c = 12
c = 6
So there are 6 chickens and 7 pigs