Here are the solutions to the problems: 8. Two brands of airconditions S and T cost GH¢3,000.00 and GH¢4,000.00 respectively. A company budgeted GH¢20,000.00 to buy air conditioners. If the company bought 5 units of brand 'S' instead of brand 'T', how much did it save? Step 1: Calculate the cost if 5 units of brand 'T' were bought. Cost per unit of brand T = GH¢4,000.00 Cost for 5 units of brand T $= 5 \times \text{GH¢}4,000.00 = \text{GH¢}20,000.00$ Step 2: Calculate the cost if 5 units of brand 'S' were bought. Cost per unit of brand S = GH¢3,000.00 Cost for 5 units of brand S $= 5 \times \text{GH¢}3,000.00 = \text{GH¢}15,000.00$ Step 3: Calculate the savings. Savings = (Cost of 5 units of T) - (Cost of 5 units of S) Savings $= \text{GH¢}20,000.00 - \text{GH¢}15,000.00 = \text{GH¢}5,000.00$ The correct option is B. $$\boxed{\text{B. GH¢}5,000.00}$$ 9. Write 73,843 to 2 significant figures. Step 1: Identify the first two significant figures. In 73,843, the first significant figure is 7 and the second is 3. Step 2: Look at the digit immediately to the right of the second significant figure. The digit is 8. Step 3: Round based on the digit identified in Step 2. Since 8 is 5 or greater, we round up the second significant figure. The 3 becomes 4. All digits to the right become zeros. Step 4: Write the rounded number. $$73,843 \approx 74,000$$ The correct option is B. $$\boxed{\text{B. } 74000}$$ 10. Express 86.90847 correct to 3 decimal places. Step 1: Identify the digit in the third decimal place. In 86.90847, the third decimal place is 8. Step 2: Look at the digit immediately to the right of the third decimal place. The digit is 4. Step 3: Round based on the digit identified in Step 2. Since 4 is less than 5, we keep the digit in the third decimal place as it is (8 remains 8). All digits to the right are dropped. Step 4: Write the rounded number. $$86.90847 \approx 86.908$$ The correct option is D. $$\boxed{\text{D. } 86.908}$$