Answer:
The number of hens is 100 and the number of roosters is 200.
Explanation:
Let the number of hens be x and the number of roosters be y
then the total number of hens and roosters, is 300
so,
----------------------------(1)
Also the hen eats 80 pounds of food per year and roosters eats 60 pounds of food per year,
----------------(2)
To solve the equations , multilpy eq(1) by 80
------------------(3)
Subracting (2) from (3)


substituting y in eq(1) we get


x = 100