1. The problem states that Madhu bought a coat costing 1800 and paid VAT, making the total price 1980. 2. We need to find the VAT amount and the VAT rate. 3. VAT amount = Total price - Cost price = 1980 - 1800 = 180. 4. VAT rate is calculated as \( \frac{\text{VAT amount}}{\text{Cost price}} \times 100 \% = \frac{180}{1800} \times 100 = 10\% \). 5. Therefore, the VAT rate is 10%.