Question

Thirteen chickens and pigs are at the backyard feeder. You count 36 legs. How many chickens and how many pigs are there?

Answer 1

13 * 2 = 26. 36 - 26 = 10
10 / 4 = 2.5
....hmmm, did I mess up somewhere? Oh well there are 2 pigs. and a messed up chicken

Answer 2

5 pigs and 8 chickens
5(4)+8(2)=36

Answer 3

The way to solve it is something like this.

Let C = # of chickens
P = # of pigs

Then C + P = 13

Now as 2C = # of chicken legs and 4P = # pig legs, we have
2C + 4P = 36.

Hence we have two equations in C and P:

C + P = 13
2C + 4P = 36

Now solve that however you normally solve such equations.