1. **State the problem:** The manager buys kites at a cost price of 25 and sells them at a selling price of 36. We need to find the mark-up percentage. 2. **Formula for mark-up percentage:** Mark-up percentage = $$\frac{\text{Selling Price} - \text{Cost Price}}{\text{Cost Price}} \times 100\%$$ 3. **Substitute the values:** Mark-up percentage = $$\frac{36 - 25}{25} \times 100\%$$ 4. **Calculate the difference:** Mark-up percentage = $$\frac{11}{25} \times 100\%$$ 5. **Simplify the fraction:** Mark-up percentage = $$\frac{\cancel{11}}{\cancel{25}} \times 100\% = 0.44 \times 100\%$$ 6. **Calculate the final percentage:** Mark-up percentage = $$44\%$$ **Answer:** The mark-up percentage is 44%.