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Wants, Factors of Production and Utility, ISC 11

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EconomicsISC Class 11 · Introduction to Economics

Wants, Factors of Production and Utility (ISC Class 11 Economics)

Updated 17 October 2026 · Fact-checked

Human wants are unlimited, recurring and competing; goods satisfy them. Four factors of production (land, labour, capital and enterprise) earn rent, wages, interest and profit. Utility is the want-satisfying power of a good; total utility (TU) is the sum of utilities from all units, marginal utility (MU) is the extra utility from one more unit, MU = TU(n) - TU(n-1), and by the law of diminishing marginal utility MU falls as consumption rises.

See that TU is highest exactly where MU reaches zero, and TU falls once MU becomes negative.

Illustration drawn for QuestionBuddy.

Understand Wants, Factors of Production, Factor Incomes and Utility

Wants. Desires backed by the wish to satisfy them. Features: unlimited; each want is satiable; competing; recurring; vary in urgency; become habits; influenced by income, taste and fashion. Classes: necessaries, comforts, luxuries.

Goods. Free goods (air) and economic goods (scarce); consumer goods and capital goods; durable and non-durable.

Factors of production and incomes.

FactorMeaningReward
LandAll natural resourcesRent
LabourHuman effort, physical or mentalWages
CapitalMan-made goods used for further productionInterest
Enterprise (entrepreneur)Organising and risk-takingProfit

Utility. The want-satisfying power of a commodity. Subjective; depends on time, place and person; different from usefulness.

Total and marginal utility. TU = sum of MU of all units. MU = change in TU from one more unit = TU(n) - TU(n-1). When MU is positive, TU rises; when MU = 0, TU is maximum (saturation); when MU is negative, TU falls.

Law of diminishing marginal utility. As a consumer takes more units of a good, the marginal utility from each additional unit falls (other things, including the quality and tastes, remain the same). Assumptions: same units of the good, continuous consumption, constant tastes, rational consumer. Exceptions: apparent exceptions such as hobbies or collection may show rising MU initially.

Price, value and wealth. *Price:* value in money. *Value in use:* utility; *value in exchange:* purchasing power. *Wealth:* stock of economically valuable goods that are scarce and transferable. *Welfare:* well-being. *Nominal vs real:* nominal at current prices; real adjusted for prices.

Wants, Factors of Production, Factor Incomes and Utility: key facts

Marginal utility
MU = TU(n) - TU(n-1) | Change in TU for one more unit
Basic definition.
Total utility
TU = MU1 + MU2 + ... + MUn | Sum of marginal utilities
Cumulative.
Saturation
MU = 0 at maximum TU | MU < 0 means TU falls
Turning point.

How to answer Wants, Factors of Production, Factor Incomes and Utility questions

Tabulate units, TU and MU and use the relation between them.

  1. 1Compute MU as the difference between successive TUs (or TU as the running sum of MU).
  2. 2Mark where MU falls to zero (TU maximum).
  3. 3Check that MU diminishes (law holds).
  4. 4Interpret in terms of consumer behaviour.

Wants, Factors of Production, Factor Incomes and Utility in real life

The idea, met in an everyday situation. Answer the question in your own words, then compare with the model answer. The one-line hook is what to remember.

Diminishing marginal utility

Suppose Raju eats samosas: the first gives 20 units of satisfaction, the second 14, the third 8, the fourth 2 and the fifth is negative.

Find the TU after each samosa and say when he should stop.

Try it first, then show the solutionSolution
  1. TU: 20, 34, 42, 44; the fifth reduces TU.
  2. He should stop after the fourth, where MU is nearly zero.

Answer: TU 20, 34, 42, 44; stop after the fourth.

Memory hook: Each extra unit gives less.

Tricks to remember Wants, Factors of Production, Factor Incomes and Utility

Short memory aids. Say each one aloud once, then use it on a question the same day.

  • L-L-C-E

    Land, Labour, Capital, Enterprise.

    Use it when: Factors.

  • R-W-I-P

    Rent, Wages, Interest, Profit.

    Use it when: Rewards.

  • MU zero, TU peak

    TU is maximum when MU is zero.

    Use it when: Relation.

Wants, Factors of Production, Factor Incomes and Utility: solved examples

Ordered from board level to HOTS. Try each one before you open the solution.

Example 1: Rewards · 1 mark · MCQBoard level

The reward for the factor "capital" is:
(a) rent (b) wages (c) interest (d) profit

Try it first, then show the solutionSolution
  1. Capital earns interest.

Answer: (c) interest

Example 2: Features of wants · 4 marks · Short answerBoard level

State four features of human wants. (4 marks)

Try it first, then show the solutionSolution
  1. Unlimited.
  2. Satiable individually.
  3. Competing.
  4. Recurring.

Answer: Wants are unlimited in number, each want can be satisfied, they compete for limited means, and they recur.

Example 3: TU and MU table · 6 marks · Long answerHarder board level

The TU from oranges is 12, 22, 30, 36, 40, 40, 36 for 1 to 7 oranges. Find the MU of each orange, the point of saturation, and state whether the law of diminishing marginal utility holds. If the price is such that the consumer values an orange at a MU of 4, how many does he buy? (6 marks)

Try it first, then show the solutionSolution
  1. MU: 12, 10, 8, 6, 4, 0, -4.
  2. Saturation: TU is maximum (40) at 5 and 6 oranges, MU = 0 at the sixth.
  3. The law holds: MU falls with every unit.
  4. At MU = 4 he stops at the fifth orange.

Answer: MU 12, 10, 8, 6, 4, 0, -4; saturation at the sixth orange; the law holds; he buys 5 oranges.

Example 4: Reconstruct the table · 5 marks · Long answerHarder board level

MU of a good is 30, 24, 18, 12, 6, 0 for units 1 to 6. Find the TU after each unit. A consumer has an income of Rs 60 and each unit costs Rs 10; find the most TU he can obtain and the units he buys. Why would he not buy the sixth unit even if it were free? (5 marks)

Try it first, then show the solutionSolution
  1. TU: 30, 54, 72, 84, 90, 90.
  2. With Rs 60 he can buy 6 units at Rs 10 each, but the sixth adds nothing (MU = 0).
  3. Maximum TU = 90 with 5 units (spending Rs 50); he keeps Rs 10.
  4. A free sixth unit adds nothing to satisfaction and has no value.

Answer: TU 30, 54, 72, 84, 90, 90; he buys 5 units; TU = 90; the sixth adds zero utility.

Example 5: Evaluate · 4 marks · Short answerHOTS / competency

A critic says the law of diminishing marginal utility fails for a person collecting stamps because each stamp makes the collection more valuable. Evaluate with two points about the assumptions of the law. (4 marks)

Try it first, then show the solutionSolution
  1. The law assumes identical units; stamps in a collection are different and complete a set, so the "unit" changes.
  2. Utility may rise at first as the set nears completion, but after completion, further identical stamps give little utility.
  3. Tastes can change: the law holds for a given, constant taste.
  4. So the exception is only apparent.

Answer: Collections break the "same unit" and "constant taste" assumptions; the law still holds for identical units after the set is complete.

Where students lose marks in Wants, Factors of Production, Factor Incomes and Utility

The slips examiners see most often, and what to write instead.

  • Mistake: MU computed as TU divided by units

    Average confusion.

    Wrong working

    12/1, 22/2

    Right working

    22 - 12

    Do this: MU is the difference.

    Usually costs: 2 marks.

  • Mistake: Saying TU falls when MU falls

    Direction mix.

    Wrong working

    MU falls so TU falls

    Right working

    TU rises at a decreasing rate while MU is positive

    Do this: TU falls only if MU is negative.

    Usually costs: 2 marks.

  • Mistake: Profit as reward of capital

    Mixed terms.

    Wrong working

    Capital - profit

    Right working

    Capital - interest

    Do this: Profit is for enterprise.

    Usually costs: 1 mark.

Exam tips

  • Draw the TU and MU table with differences.
  • State assumptions of the law.
  • Note where MU = 0 and TU is maximum.

Practice questions on Wants, Factors of Production, Factor Incomes and Utility

Write each answer on paper first. Open the hint only if you are stuck, and the answer only when you have finished.

  1. Q1 · 1 mark · MCQBoard level

    When marginal utility is zero, total utility is:
    (a) zero (b) maximum (c) negative (d) minimum

    Hint

    Saturation.

    Answer

    (b) maximum

  2. Q2 · 3 marks · Short answerBoard level

    Explain any three assumptions of the law of diminishing marginal utility. (3 marks)

    Hint

    Same units, constant taste, continuity.

    Answer

    The units are identical and consumed continuously; the consumer's tastes and income are constant; the consumer is rational and uses standard units.

  3. Q3 · 3 marks · Short answerHarder board level

    TU of mangoes: 1 unit 18, 2 units 32, 3 units 42, 4 units 48, 5 units 50. Find the MU of each mango and the change in TU when the sixth mango has an MU of -2. (3 marks)

    Hint

    Differences.

    Answer

    MU: 18, 14, 10, 6, 2. The sixth with MU -2 lowers TU from 50 to 48. The law holds as MU falls steadily.

  4. Q4 · 5 marks · Long answerHarder board level

    A consumer's marginal utility from a good is 16, 12, 8, 4, 0 utils for units 1 to 5. Each unit costs Rs 8 and a rupee is worth 0.5 util to him (MU of money). How many units does he buy? Show TU, and the utility given up when paying for 4 units. (5 marks)

    Hint

    Buy until MU equals price x MU of money.

    Answer

    Utility value of a unit's price = 8 x 0.5 = 4 utils. He buys while MU is at least 4: units 1 to 4 (MU 16, 12, 8, 4); at the fifth MU is 0, below 4. He buys 4 units. TU = 16 + 12 + 8 + 4 = 40 utils. Money spent = Rs 32, worth 32 x 0.5 = 16 utils given up, so net gain = 24 utils.

  5. Q5 · 4 marks · Short answerHOTS / competency

    A farm family has a plot of land, two adults, a tractor and an elder who decides the crops and bears the risk. Identify the factors of production and their rewards, and say who earns profit. (4 marks)

    Hint

    Four factors.

    Answer

    Land earns rent, the adults' labour earns wages, the tractor (capital) earns interest, and the elder who organises and bears risk is the entrepreneur earning profit.

Test your recall

Answer in your head or on paper first, then open the card. Pulling an answer out of memory makes it stick far better than re-reading.

  1. 1.Reward for land?Show answer

    Rent.

  2. 2.MU formula?Show answer

    TU(n) - TU(n-1).

  3. 3.TU maximum when?Show answer

    MU is zero.

  4. 4.Four factors?Show answer

    Land, labour, capital, enterprise.

  5. 5.Wants are?Show answer

    Unlimited and recurring.

Wants, Factors of Production, Factor Incomes and Utility: frequently asked questions

Is utility same as usefulness?

No, utility is subjective satisfaction.

Is capital man-made?

Yes.

Can MU be negative?

Yes, beyond saturation.

What is a free good?

A good not scarce, like air.