A manufacturer sells an item to a wholesale dealer at a profit of 18%. The wholesaler sells the same to a retailer at a profit of 16%. The retailer in turn sells it to a customer for Rs.32,851.2 thereby earning a profit of 20%. Find the cost price of the manufacturer.

Correct option is D

​$$\text{Let } C_r \text{ be the retailer's cost price.} \\[6pt]32851.2 = C_r \times \left(1 + \frac{20}{100} \right) \\[6pt]32851.2 = C_r \times 1.2 \\[6pt]C_r = \frac{32851.2}{1.2} \\[6pt]C_r = 27376$$

$$\text{Let } C_w \text{ be the wholesaler's cost price.} \\[6pt]27376 = C_w \times \left(1 + \frac{16}{100} \right) \\[6pt]27376 = C_w \times 1.16 \\[6pt]C_w = \frac{27376}{1.16} \\[6pt]C_w = 23600 \\[12pt]\textbf{Step 3} \\[6pt]\text{Let } C_m \text{ be the manufacturer's cost price.} \\[6pt]23600 = C_m \times \left(1 + \frac{18}{100} \right) \\[6pt]23600 = C_m \times 1.18 \\[6pt]C_m = \frac{23600}{1.18} \\[6pt]C_m = 20000$$​​​