1. **State the problem:** The factory fills 750 ml containers using 900 litres of juice in one day. There are 4 times as many 100 ml containers filled as 750 ml containers each day. We need to find how many litres of juice are filled from Monday to Friday. 2. **Identify given data:** - Volume used for 750 ml containers per day = 900 litres - Ratio of 100 ml containers to 750 ml containers = 4:1 - Number of days = 5 (Monday to Friday) 3. **Calculate the number of 750 ml containers filled per day:** Since each 750 ml container holds 0.75 litres, the number of 750 ml containers filled per day is: $$\text{Number of 750 ml containers} = \frac{900}{0.75} = 1200$$ 4. **Calculate the number of 100 ml containers filled per day:** There are 4 times as many 100 ml containers, so: $$\text{Number of 100 ml containers} = 4 \times 1200 = 4800$$ 5. **Calculate the total volume of juice used for 100 ml containers per day:** Each 100 ml container holds 0.1 litres, so: $$\text{Volume for 100 ml containers} = 4800 \times 0.1 = 480 \text{ litres}$$ 6. **Calculate total juice used per day:** $$\text{Total juice per day} = 900 + 480 = 1380 \text{ litres}$$ 7. **Calculate total juice used from Monday to Friday (5 days):** $$\text{Total juice for 5 days} = 1380 \times 5 = 6900 \text{ litres}$$ **Final answer:** $$\boxed{6900 \text{ litres}}$$ **Note:** The answer 19200 litres given in the question seems incorrect based on the data and calculations above.