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Question

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R

Assertion A: For a demand function $P = 60 - Q^2$ and at price $P = 44$, point elasticity of demand is $-1.375$.

Reason R: Demand is inelastic.

In the light of the above statements, choose the most appropriate answer from the options given below

The correct answer is
A is correct but R is not correct

Assertion A Verification

We are given the demand function $P = 60 - Q^2$ and a specific price $P = 44$. First, we need to find the corresponding quantity $Q$.

  • Substitute $P = 44$ into the demand function:

    $44 = 60 - Q^2$

  • Solve for $Q^2$:

    $Q^2 = 60 - 44$

    $Q^2 = 16$

  • Find $Q$ (assuming quantity is positive):

    $Q = \sqrt{16} = 4$

Next, we calculate the point elasticity of demand ($E_d$). The formula is:

$E_d = \frac{dQ}{dP} \times \frac{P}{Q}$

First, find the derivative of $P$ with respect to $Q$:

$P = 60 - Q^2 \implies \frac{dP}{dQ} = -2Q$

Now, find the derivative of $Q$ with respect to $P$:

$\frac{dQ}{dP} = \frac{1}{\frac{dP}{dQ}} = \frac{1}{-2Q}$

Substitute $Q=4$ into the expression for $\frac{dQ}{dP}$:

$\frac{dQ}{dP} = \frac{1}{-2(4)} = -\frac{1}{8}$

Finally, calculate the point elasticity of demand using $P=44$, $Q=4$, and $\frac{dQ}{dP} = -\frac{1}{8}$:

$E_d = \left(-\frac{1}{8}\right) \times \left(\frac{44}{4}\right)$

$E_d = -\frac{1}{8} \times 11 = -\frac{11}{8}$

Convert the fraction to a decimal:

$E_d = -1.375$

Conclusion for Assertion A: The calculated point elasticity is $-1.375$, which matches the value stated in Assertion A. Therefore, Assertion A is correct.

Reason R Verification

Reason R states that demand is inelastic. To determine if demand is elastic or inelastic, we look at the absolute value of the price elasticity of demand ($|E_d|$).

  • Calculated elasticity: $E_d = -1.375$.
  • Absolute value: $|E_d| = |-1.375| = 1.375$.

The interpretation of elasticity is as follows:

  • If $|E_d| > 1$, demand is elastic.
  • If $|E_d| < 1$, demand is inelastic.
  • If $|E_d| = 1$, demand is unit elastic.

Since $|E_d| = 1.375$, which is greater than 1, the demand is elastic at the given price point, not inelastic.

Conclusion for Reason R: Reason R is incorrect.

Final Answer Derivation

Based on the analysis:

  • Assertion A is correct.
  • Reason R is incorrect.

This corresponds to Option C.

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Important Questions from Mixed Topic (CUET PG)

  1. Who was the founder of Bolshevik Communist party?
  2. What is the key guide to statecraft in the realist tradition?
  3. Chronologically arrange the events in the Cold War period.
    A. Berlin Wall is constructed
    B. Communist China joins the UN
    C. Soviet invasion of Czechoslovakia
    D. Berlin Blockade
    Choose the correct answer from the options given below:
  4. Morgenthau's principles of political realism are:
    A. Politics is rooted in permanent and unchanging human nature which is basically self centred, self-regarding and self-interested
    B. Politics is an autonomous sphere of action and cannot therefore be reduced to morals
    C. International Politics is an arena of conflicting self-interests
    D. The ethics of international relations is situational ethics which is very different from private morality
    Choose the correct answer from the options given below:

  5. Who among the following political thinkers consider the anarchical self help system to be a compelling factor for States to maximise their relative power positions?

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