See attached. The trick is to use similar triangles.
Answer:
22/3=8/3=2.66
if 12 servings =2.6 cup of flour
...18 servings=???????
18×2.6/12=3.9
the answer is 3.9
22 x 85 = (20+2)*85= 20*85+ 2*85 = 1700 + 170 = 1870
P(t)=number of sheet of paper after t minutes.
p(t) will have to be equal to 0, wnen the printer use all 100 sheets of paper;
Therefore;
if p(t)=0
Then:
-8t+100=0
We solve this equation.
-8t+100=0
8t=100
t=100/8
t=12.5
Answer: the printer prints 100 sheets of paper in 12.5 minutes.