By adding all the marginal products at each level of employment of the variable input, we obtain a value equal to

Analyze the question: The question asks what you get when you add up (sum) all the marginal products as you employ more units of a variable input.

Concept:

• Marginal product (MP) is the extra output gained from employing one more unit of the variable input: MP = ΔTP / ΔL
• Total product (TP) is the total output produced at a given level of input employment.
• Average product (AP) = TP / number of units of the variable input.

Since MP is the addition to total output from each extra unit of input, then adding the MPs together rebuilds the total output.

Solution (with an example):

| Labour | Total Product | Marginal Product | |---|---|---| | 1 | 10 | 10 | | 2 | 24 | 14 | | 3 | 36 | 12 | | 4 | 44 | 8 |

Summing the MPs up to 4 workers: 10 + 14 + 12 + 8 = 44, which is exactly the Total Product at 4 workers.

So: TP = ΣMP

Checking the other options:

• A. Average product is TP divided by the input, so it is not a sum of MPs.
• C. Average variable cost is a cost concept (TVC/output), not an output sum.
• D. Total cost is a cost measure (fixed + variable cost), not related to summing MPs.

Correct answer: B. Total product

Tip: Remember "MP adds up to TP." Marginal means "extra," and when you add all the extras, you get the total. In the same way, adding all the marginal costs gives you total variable cost.