Relation between AR, MR and elasticity of demand can be established by the formula

$$MR = ARleft( {1 - rac{1}{e}} ight)$$
$$AR = MRleft( { rac{{e - 1}}{e}} ight)$$
$$MR = ARleft( { rac{1}{{e - 1}}} ight)$$
$$AR = left( { rac{{MR}}{e}} ight)$$

The correct answer is: A. $$MR = AR\left( {1 – \frac{1}{e}} \right)$$

The formula for marginal revenue (MR) is:

$$MR = \frac{dQ}{dP} \cdot P$$

The formula for average revenue (AR) is:

$$AR = \frac{TR}{Q} = P$$

The formula for elasticity of demand (e) is:

$$e = \frac{dQ}{dP} \cdot \frac{P}{Q}$$

Therefore, the formula for MR in terms of AR and e is:

$$MR = AR\left( {1 – \frac{1}{e}} \right)$$

Here is a brief explanation of each option:

  • Option A: This is the correct formula. It is derived from the formulas for MR, AR, and e.
  • Option B: This formula is incorrect. It does not take into account the elasticity of demand.
  • Option C: This formula is incorrect. It does not take into account the price.
  • Option D: This formula is incorrect. It does not take into account the quantity demanded.