Answer:

Step-by-step explanation:
We will prove by mathematical induction that, for every natural n,

We will prove our base case (when n=1) to be true:
Base case:
As stated in the qustion, 
Inductive hypothesis:
Given a natural n,

Now, we will assume the inductive hypothesis and then use this assumption, involving n, to prove the statement for n + 1.
Inductive step:
Let´s analyze the problem with n+1 stones. In order to move the n+1 stones from A to C we have to:
- Move the first n stones from A to C (
moves). - Move the biggest stone from A to B (1 move).
- Move the first n stones from C to A (
moves). - Move the biggest stone from B to C (1 move).
- Move the first n stones from A to C (
moves).
Then,
.
Therefore, using the inductive hypothesis,

With this we have proved our statement to be true for n+1.
In conlusion, for every natural n,

For twelve people you need: 2 litres of lemon-lime soda, 1 pint of sherbet and 3 cups of ice tea.
For 36 people you need: 6 litres of lemon-lime soda, 3 pints of sherbet and 9 cups of ice.
9/20 plus 3/20 equals to 12/20, which is equal to 6/10, which is equal to 3/5
Y = mx + b
m is -1/3
plug in your given values for x and y to find b
1 = (-1/3)(0) + b
1 = 0 + b
b = 1
make equation
y= (-1/3)x + 1