A farmer raises cows and chickens. The farmer has a total of 21 animals. One day he counts the legs of all his animals and realizes he has a total of 62 legs. How many of each animal does he have?

Answer 1

4 w + 2 k = 62

w + k = 21

solve using substitution
... or elimination

Answer 2

say that all 21 are chickens. That would give 42 legs.

Each chicken that is replaced with a cow will raise the leg count by 2.

we have 20 extra legs, so that means we need 10 cows.

Thus, 11 chickens, 10 cows