1. Problem: Add 700 m and 3.7 km, express the sum in meters. Step 1: Convert 3.7 km to meters since 1 km = 1000 m. $$3.7 \times 1000 = 3700 \text{ m}$$ Step 2: Add 700 m and 3700 m. $$700 + 3700 = 4400 \text{ m}$$ Final answer: The total length is $4400$ meters. 2. Problem: Find the weight of 5000 tea bags if 70 tea bags weigh 180 g. Step 1: Find weight of one tea bag. $$\frac{180}{70} = 2.5714 \text{ g per tea bag}$$ Step 2: Multiply weight per tea bag by 5000. $$2.5714 \times 5000 = 12857.14 \text{ g}$$ Step 3: Convert grams to kilograms (1000 g = 1 kg). $$\frac{12857.14}{1000} = 12.85714 \text{ kg}$$ Final answer: 5000 tea bags weigh approximately $12.86$ kg. 3. Problem: Find the weight of 8000 tea bags if 90 tea bags weigh 3500 g. Step 1: Weight per tea bag. $$\frac{3500}{90} = 38.8889 \text{ g per tea bag}$$ Step 2: Weight of 8000 tea bags. $$38.8889 \times 8000 = 311111.11 \text{ g}$$ Step 3: Convert grams to kilograms. $$\frac{311111.11}{1000} = 311.1111 \text{ kg}$$ Final answer: 8000 tea bags weigh approximately $311.11$ kg. 4. Problem: Calculate total litres of drink made from 850 ml strawberry plus water with ratio 2:6. Step 1: Total parts = $2 + 6 = 8$ parts. Step 2: Each part's volume in ml. $$\frac{850}{2} = 425 \text{ ml per part}$$ Step 3: Total volume in ml. $$425 \times 8 = 3400 \text{ ml}$$ Step 4: Convert ml to litres (1000 ml = 1 litre). $$\frac{3400}{1000} = 3.4 \text{ litres}$$ Final answer: One bottle makes $3.4$ litres of the drink.