Rani buys toys at 6 for a rupee and sells them at 3 for a rupee. Her profit is:

Correct option is D

Given:

Cost price (CP): Rani buys 6 toys for 1 rupee.
Selling price (SP): Rani sells 3 toys for 1 rupee.

Formula Used:

Cost Price per Toy:

​$$\text{CP per Toy} = \frac{\text{Total Cost}}{\text{Number of Toys}}$$​​

Selling Price per Toy:

​$$\text{SP per Toy} = \frac{\text{Total Selling Price}}{\text{Number of Toys}}$$​​

Profit per Toy:

​$$\text{Profit per Toy} = \text{SP per Toy} - \text{CP per Toy}$$​​

Profit Percentage:

​$$\text{Profit Percentage} = \frac{\text{Profit per Toy}}{\text{CP per Toy}} \times 100$$​​

Solution:

Calculate CP per toy:

​$$\text{CP per Toy} = \frac{1 \text{ rupee}}{6} = \frac{1}{6} \text{ rupee}$$​​

Calculate SP per toy:

​$$\text{SP per Toy} = \frac{1 \text{ rupee}}{3} = \frac{1}{3} \text{ rupee}$$​​

Calculate Profit per toy:

​$$\text{Profit per Toy} = \frac{1}{3} - \frac{1}{6} = \frac{1}{6} \text{ rupee}$$​​

Calculate Profit Percentage:

​$$\text{Profit Percentage} = \frac{\frac{1}{6}}{\frac{1}{6}} \times 100 = 100\%$$​​