Opportunity Cost from a PPC Table: Class 11 Numericals

A production possibility table may ask how many units of one good must be sacrificed to make more of another. The common mistake is to divide the two numbers in the same row. Opportunity cost comes from the change between two combinations, not from their output totals.

This Class 11 Economics guide uses an original teaching schedule, not data from a real workshop. CBSE's 2026-27 Economics curriculum includes production possibility frontier and opportunity cost in Introductory Microeconomics. We will calculate a single-step cost, a cost across several steps and the reverse trade-off.

Read the production possibilities first

Assume a workshop has fixed resources and technology for one day. It can use them to make notebooks or folders. Each combination below uses those resources fully and efficiently. Moving between the combinations reallocates the same resources; it does not add workers or improve the machines.

Table 1: scroll horizontally to see all columns.

Read B as “2 notebooks and 36 folders,” not a choice between those quantities. To move from B to C, the workshop gains notebooks and gives up folders. Always write the direction of the move before calculating.

Calculate the cost per additional notebook

Opportunity cost per notebook = folders forgone ÷ notebooks gained. Use the positive amount forgone. A signed graph slope is a different way of expressing the downward trade-off.

For B to C, notebooks gained = 4 - 2 = 2. Folders forgone = 36 - 28 = 8. Therefore the opportunity cost is 8 ÷ 2 = 4 folders per additional notebook.

The total sacrifice for this move is 8 folders. The per-notebook cost is 4 folders. Both answers describe the same move, but they answer different questions. Dividing 28 by 4 would give a ratio of output totals at C, not the cost of changing production.

Check the result backwards: 2 extra notebooks × 4 folders per notebook = 8 folders forgone. Starting from 36 folders leaves 28, which matches C.

Complete the marginal opportunity cost column

The notebook gain is two units at each step. Divide the folder loss by two each time:

• A to B: (40 - 36) ÷ (2 - 0) = 2 folders per notebook.
• B to C: (36 - 28) ÷ (4 - 2) = 4 folders per notebook.
• C to D: (28 - 16) ÷ (6 - 4) = 6 folders per notebook.
• D to E: (16 - 0) ÷ (8 - 6) = 8 folders per notebook.

These are per-unit costs over each listed interval. The table does not tell us how cost changes within a two-notebook interval, so do not invent separate costs for its first and second notebook. If a question labels the column MOC or MRT, check whether it wants the sacrifice for the whole listed increase or the sacrifice per unit. State your units explicitly.

A longer move gives an average over that interval

From B to D, notebooks increase from 2 to 6 and folders fall from 36 to 16. The sacrifice is 20 folders for 4 notebooks, so the average opportunity cost over this move is 5 folders per notebook.

That does not make the B-to-C cost 5. The two equal-sized steps cost 4 and 6 folders per notebook; their average is 5. If the notebook gains differed between steps, a simple unweighted average could be wrong. Calculate total loss divided by total gain instead.

Reverse the direction and the units

Now move from C back to B. The workshop gains 8 folders and gives up 2 notebooks. Cost per additional folder = 2 ÷ 8 = 0.25 notebook per folder. This is the reciprocal of 4 folders per notebook for the same interval.

Do not take reciprocals across different intervals. B-to-C and D-to-E have different trade-offs in this schedule.

Explain the pattern without overclaiming

The rising per-notebook costs illustrate increasing opportunity cost. Resources are not equally suited to both activities, so successive reallocations can sacrifice more alternative output. A bowed-out frontier is consistent with that pattern; a straight-line frontier represents constant opportunity cost instead.

An inside point reflects unused or inefficiently used productive capacity. Moving toward the frontier is not the same as shifting it outward. More resources or improved technology can expand the production possibilities. For study support across commerce subjects, see our guide to choosing commerce tuition.

Frequently asked questions

Is opportunity cost always a money payment?

No. It is the value of the next-best alternative forgone. In a production table, express it in units of the other good.

Why not divide the outputs in one row?

One row describes a production combination. The cost of moving to another combination depends on output changes between the rows.

Does marginal opportunity cost always increase?

No. This schedule illustrates increasing cost. A straight-line production possibility frontier has constant opportunity cost.

Can I find each one-unit cost from a two-unit step?

Not separately without more information. Dividing loss by gain gives the average per-unit cost over the stated interval.

Sources

• CBSE Economics curriculum 2026-27: Class 11 Introductory Microeconomics scope.
• NCERT Introductory Microeconomics, Introduction: production possibilities, scarcity and opportunity cost.
• OpenStax: production possibilities and social choices: opportunity cost and frontier interpretation.