Answer:

Step-by-step explanation:
In the Equation it asks for 3 things; pi (3.14), r (The radius), and h (the height).
In the question, it says that the radius is 1 foot and that the height is 4 feet. From there all you need to do is insert those numbers where it's shown in the equation. This makes the equation go from this:

To this: 
From there you follow PEMDAS/GEMDAS. And should have your answer.
The Answer to this is 10 seconds
The answer is 200%.
( Take 600 divided by 300 )
4$-20%
X$-100%
X=4·100:20=400:20=20
Answer : He paid for the meal 20$.