Answer:
5 days
Explanation:
Set up linear equation; food= 240-12(day) f=240-12d
f(1)=240-12(1)=240-12=228
f(2)=240-12(2)=240-24=216
Now set food to equal 180, solve for days:
180=240-12d
-240 -240
-60=-12d
/-12 /-12
5=d
To check: f(5)=240-12(5)=240-60=180