What percent of water must be mixed with honey so as to gain 20% by selling the mixture at the cost price of honey?

1. **Identify the Goal:** We need to find the percentage of water mixed with honey to get a 20% profit, selling at the Cost Price (CP) of honey.\n\n2. **Analyze Costs (Using PYQ Context):**\n - As per standard 'Gain' concepts [13, 16], profit is based on investment (Cost Price).\n - Investment = Cost of Honey (Water is free, similar to assumptions in [10]).\n\n3. **Apply Logic (The Elegant Shortcut):**\n - We are selling the mixture at the same rate we bought the honey.\n - Therefore, the money we get back for the honey part just covers our cost (0% profit).\n - The *entire* 20% profit must come from the money we get for the water.\n - Since the selling price is the same for both parts, to get 20% extra money (profit), we simply need 20% extra volume.\n\n4. **Conclusion:**\n - Volume of Water = 20% of Volume of Honey.\n - This matches option (a).