1. Input vs. Output

2. Input vs. Output
Output problems state that you get a certain amount of product out of a given input.
Examples miles per gallon, pieces of gum per dollar...
Input problems state that it takes a certain amount of input to get a given product.
Examples are hours to do a job, apples to make a pie,

3. Absolute Advantage
For output problems you look at if one nation (individual/company) can produce more output with the same resources as the other.
Examples: Output: (Tons produced per hour)
Milk
Cheese
Ted 70 15
Nancy 40 45

4. Comparative Advantage
One nation (individual/company) can produce a good at a lower opportunity cost than the other.
This comes into play when one individual (nation, company....) has the absolute advantage in both.

5. Comparative Advantage
Output method: put the output of each product over the output of the other product for the same person. This makes a fraction. Look at the opportunity cost. The person with the lowest opportunity cost should produce the good that costs the least.
Corn
Wheat
Mike 8 6
John 2 4

6. Comparative Advantage
Put the output of each product over the output of the other product.
Corn
Wheat
Mike
6/8
8/6
John
4/2
2/4
Corn
Wheat
Mike
3/4
4/3
John 2
1/2

7. Comparative Advantage
Pie
Juice
Jeff 5 3
Judy 6
Pie
Juice
Jeff
5/3
3/5
Judy
6/3
3/6
Input Method: divide the input required for each product into the input for the other product. Then take the one with the lowest opportunity cost
Reduce it:  5/3 is less than 6/3 so Jeff should produce pie. 3/6 is less than 3/5 so Judy should produce Juice.