farmland

1c = 2g

or    c = 2g

3g=5f     (f= chickens)

g=5/3f     Substitute into the first equation

c = 2 (5/3 f)       now you have 6 cows so multiply both sides by 6

6c = (6)(2)(5/3 f) = 60/3 f = 20 f   

6 cows = 20 chickens

5 / 3 = 1 2/3 chickens per goat.

1 2/3 x 2 = 3 1/3 chickens per cow.

3 1/3 x 6 = 20 chickens for 6 cows!!.