A math teacher drove past a farmyard that was full of chickens and pigs The teacher just happened to notice that there were a total of 70 heads and 200 legs How many chickens and pigs were there?

Answer 1

This problem can be solved using a series of linear equations.

First, know that each animal has one head, each pig has four legs, and each chicken has 2 legs.

Let the variable p represent the number of pigs, and the variable c represent the number of chickens.

p+c=70 (that's from knowing each animal has one head)

4p+2c=200 (that's from knowing the number of legs each animal has)

If we isolate c in the first equation, we get:

p+c=70

c=70-p

Putting that information into the second equation, we get:

4p+2(70-p)=200

4p+140-2p=200

2p=60

p=30

Finally, let's put that information into the first equation (we could put it into the second equation, but the mechanics would be more difficult).

p+c=70

30+c=70

c=40

Therefore there are 40 chickens and 30 pigs.