1. Question 9: Calculate the change received after buying 3 books costing 45.75 each with a 200 note. Step 1: Find the total cost by multiplying the price of one book by 3: $$ 3 \times 45.75 = 137.25 $$ Step 2: Subtract the total cost from the amount paid to find the change: $$ 200 - 137.25 = 62.75 $$ Answer: The student receives 62.75 change. 2. Question 10: Estimate the total distance swum if the pool is 12.5 m long and swimmer completes 9 lengths. Step 1: Calculate the exact distance swum by multiplying length by number of lengths: $$ 12.5 \times 9 = 112.5 \text{ meters} $$ Step 2: Round the answer to 3 significant figures. Since 112.5 has 4 significant digits, round to 3: $$ 113 \text{ meters} $$ Answer: The estimated total distance swum is 113 meters. 3. Question 11: Calculate liters in 12 packets of juice. a) Exact calculation: Step 1: Multiply quantity per packet by number of packets: $$ 1.35 \times 12 = 16.2 \text{ liters} $$ Answer: Exactly 16.2 liters. b) Estimate by rounding 1.35 liters to 1 decimal place: Step 1: Round 1.35 to 1 decimal place: $$ 1.4 \text{ liters} $$ Step 2: Multiply estimate by 12: $$ 1.4 \times 12 = 16.8 \text{ liters} $$ Answer: Estimated total is 16.8 liters. 4. Question 12: Is \(3.785 \div 0.1\) equivalent to \(37.85 \div 10\)? Step 1: Compute each division: $$ 3.785 \div 0.1 = 3.785 \times 10 = 37.85 $$ $$ 37.85 \div 10 = 3.785 $$ Step 2: Compare results: \(37.85 \neq 3.785\) Answer: Ahmed's statement is false because dividing by 0.1 multiplies by 10, whereas dividing by 10 reduces the number by a factor of 10. 5. Question 13: Comparing numbers. Since no specific pairs of numbers were given, no comparison statements can be made here.