1. **State the problem:** Amin wants to buy a water tank with a marked price of 32000 shillings and is given a 20% discount. 2. **Formula for discount price:** The price paid after discount is given by $$\text{Price paid} = \text{Marked price} - \text{Discount amount}$$ where $$\text{Discount amount} = \text{Discount rate} \times \text{Marked price}$$ 3. **Calculate the discount amount:** $$\text{Discount amount} = 0.20 \times 32000 = 6400$$ 4. **Calculate the price Amin pays:** $$\text{Price paid} = 32000 - 6400 = 25600$$ 5. **Conclusion:** Amin pays 25600 shillings for the water tank after the discount.