Anne made a semi-circular table cloth. The diameter of the table cloth was 42 cm. She binded the edge of the table cloth with a ribbon. What was the length of the ribbon used?

Here are the solutions to the questions: 10. Anne made a semi-circular table cloth. The diameter of the table cloth was 42 cm. She binded the edge of the table cloth with a ribbon. What was the length of the ribbon used? Step 1: Identify the components of the edge of a semi-circular table cloth. The edge consists of two parts: • The curved part, which is half the circumference of a full circle. • The straight part, which is the diameter of the semi-circle. Step 2: Calculate the length of the curved part. The circumference of a full circle is given by C = d. For a semi-circle, the curved length is (1)/(2) d. Given diameter d = 42 cm. We will use = (22)/(7). Curved length = (1)/(2) × (22)/(7) × 42 Curved length = (1)/(2) × 22 × 6 Curved length = 11 × 6 = 66 cm Step 3: Calculate the total length of the ribbon. Total ribbon length = Curved length + Diameter Total ribbon length = 66 cm + 42 cm Total ribbon length = 108 cm Step 4: Compare with the given options. The calculated length is 108 cm, which matches option B. The final answer is B. 108 cm. 11. A milk company sells yoghurt in cylindrical cups. Each cup has a diameter of 7 cm and a height of 10 cm. The company sold 385 litres of yoghurt. How many cups of yoghurt were sold? Step 1: Calculate the radius of a single cup. Diameter d = 7 cm. Radius r = (d)/(2) = (7)/(2) = 3.5 cm. Step 2: Calculate the volume of one cylindrical cup. The formula for the volume of a cylinder is V = r^2 h. We will use = (22)/(7). V_cup = (22)/(7) × (3.5)^2 × 10 V_cup = (22)/(7) × (3.5 × 3.5) × 10 V_cup = (22)/(7) × 12.25 × 10 V_cup = 22 × 1.75 × 10 V_cup = 38.5 × 10 = 385 cm^3 Step 3: Convert the total volume of yoghurt sold from litres to cubic centimeters. Given total volume sold = 385 litres. Since 1 litre = 1000 cm^3: Total volume sold = 385 × 1000 = 385000 cm^3 Step 4: Calculate the number of cups sold. Number of cups = Total volume soldVolume of one cup Number of cups = 385000 cm^3385 cm^3/cup Number of cups = 1000 Step 5: Compare with the given options. The calculated number of cups is 1000, which matches option C. The final answer is C. 1000. 12. Nyaboke walked from her home to the market. She walked at a speed of 4 km/h and took 30 minutes to reach the market. On her way back, she took 40 minutes to reach home. What was Nyaboke's speed on her way back? Step 1: Calculate the distance from home to the market. Speed to market S_1 = 4 km/h. Time to market T_1 = 30 minutes. Convert minutes to hours: 30 minutes = (30)/(60) hours = 0.5 hours. Distance D = S_1 × T_1 D = 4 km/h × 0.5 h D = 2 km Step 2: Calculate Nyaboke's speed on her way back. The distance back home is the same, D = 2 km. Time taken on the way back T_2 = 40 minutes. Convert minutes to hours: 40 minutes = (40)/(60) hours = (2)/(3) hours. Speed on the way back S_2 = (D)/(T_2) S_2 = 2 km(2)/(3) h S_2 = 2 × (3)/(2) km/h S_2 = 3 km/h Step 3: Compare with the given options. The calculated speed is 3 km/h, which matches option B. The final answer is B. 3 km/h. 13. Mueni measured the temperature of a liquid as 48^C. Which of the following calculations gives the correct temperature in Kelvin? Step 1: Recall the formula for converting temperature from Celsius to Kelvin. The formula to convert a temperature in degrees Celsius (^C) to Kelvin (K) is: K = ^ C + 273.15 Often, for simplicity or in certain contexts, 273 is used instead of 273.15. Step 2: Apply the formula to the given temperature. Given temperature is 48^C. Using the approximation K = ^ C + 273: K = 48 + 273 K = 273 + 48 Step 3: Compare with the given options. Option A, 273 + 48, correctly represents this conversion. The final answer is A. 273 + 48. 3 done, 2 left today. You're making progress.