1. **State the problem:** Mrs Lim starts with 35 liters of water. She uses $\frac{3}{7}$ of it to wash dishes, then uses $\frac{1}{4}$ of the remaining water to water flowers. We need to find how much water is left after these uses. 2. **Use the formula and rules:** - First, find the amount used for washing dishes: $\text{Water for dishes} = \frac{3}{7} \times 35$ - Then, find the remaining water after washing dishes: $\text{Remaining} = 35 - \text{Water for dishes}$ - Next, find the amount used for watering flowers: $\text{Water for flowers} = \frac{1}{4} \times \text{Remaining}$ - Finally, find the water left: $\text{Water left} = \text{Remaining} - \text{Water for flowers}$ 3. **Calculate step-by-step:** - Water for dishes: $$\frac{3}{7} \times 35 = 3 \times \frac{35}{7} = 3 \times 5 = 15$$ - Remaining water after dishes: $$35 - 15 = 20$$ - Water for flowers: $$\frac{1}{4} \times 20 = 5$$ - Water left: $$20 - 5 = 15$$ 4. **Explain the bar model:** - The bar is divided into 7 equal parts representing 35 liters, so each unit is $\frac{35}{7} = 5$ liters. - The first 3 units (3 x 5 = 15 liters) are used for dishes. - The remaining 4 units (4 x 5 = 20 liters) are left after dishes. - From these 20 liters, $\frac{1}{4}$ (which is 5 liters) is used for flowers. - The leftover water is $20 - 5 = 15$ liters. **Final answer:** Mrs Lim has **15 liters** of water left.