Answer:
The number of hens is 100 and the number of roosters is 200.
Step-by-step 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,
[tex]x+y \leq 300[/tex]----------------------------(1)
Also the hen eats 80 pounds of food per year and roosters eats 60 pounds of food per year,
[tex]80x+60y \leq 20000[/tex]----------------(2)
To solve the equations , multilpy eq(1) by 80
[tex]80x +80y \leq 24000[/tex]------------------(3)
Subracting (2) from (3)
[tex]20y \leq 4000[/tex]
[tex]y \leq 200[/tex]
substituting y in eq(1) we get
[tex]x+200 \leq300[/tex]
[tex]x \leq300 - 200[/tex]
x = 100