A fruit seller buys lemons at 2 for a rupee and sells them at 5 for three rupees. His profit percent is

### Concept & Formula To find the exact profit percent, establish the cost and selling price per unit. $$Profit \% = \left( \frac{\text{Profit}}{CP} \right) \times 100$$ ### Step-by-Step Solution * **Given:** Lemons bought at 2 for ₹ 1. Sold at 5 for ₹ 3. * **Calculation:** 1. CP of 1 lemon = $\frac{1}{2} = \text{₹ } 0.50$ 2. SP of 1 lemon = $\frac{3}{5} = \text{₹ } 0.60$ 3. Profit per lemon = $0.60 - 0.50 = \text{₹ } 0.10$ 4. Profit \% = $\left( \frac{0.10}{0.50} \right) \times 100 = \left( \frac{1}{5} \right) \times 100 = 20\%$ ### Exam Strategy & Shortcut Use the cross-multiplication shortcut for rates: Buy: 2 qty for 1 ₹ Sell: 5 qty for 3 ₹ CP base = $5 \times 1 = 5$ SP base = $2 \times 3 = 6$ Profit = $6 - 5 = 1$. Profit \% = $\frac{1}{5} \times 100 = 20\%$. ### Common Pitfall Confusing the quantity and price variables in the cross-multiplication method. Always write Quantity first, then Price, and cross-multiply upwards. ### Final Answer Therefore, the correct answer is **20**.