A certain farm has horses, which have four feet each, ostriches, which have two feet each, and no other animals.

Question

If all animals on the farm together have 324 feet and 100 heads, how many horses are there?

Answer 1

x=# of horses

y=# of ostriches

x+y=100 eq 1

4x+2y = 324 eq 2

y=100-x

substitute y into eq 2

4x+2(100-x) = 324

4x+200-2x =324

2x = 124

x=62

There are 62 horses