1. Problem: Calculate $8 \div \left(\frac{3}{4} \times \frac{1}{3}\right)$. Step 1: Multiply the fractions in the denominator: $\frac{3}{4} \times \frac{1}{3} = \frac{3 \times 1}{4 \times 3} = \frac{3}{12} = \frac{1}{4}$. Step 2: Divide 8 by $\frac{1}{4}$, which is the same as multiplying 8 by 4: $8 \times 4 = 32$. Answer: None of the options match 32, so the correct answer is not listed. 2. Problem: Calculate $\frac{2}{3}$ of 6 plus $\frac{4}{5}$ of 5. Step 1: Calculate $\frac{2}{3} \times 6 = 4$. Step 2: Calculate $\frac{4}{5} \times 5 = 4$. Step 3: Add the results: $4 + 4 = 8$. Answer: 8 (Option 1). 3. Problem: Calculate 25% of 80. Step 1: Convert 25% to decimal: $0.25$. Step 2: Multiply: $0.25 \times 80 = 20$. Answer: 20 (Option 3). 4. Problem: Calculate 75% of 96. Step 1: Convert 75% to decimal: $0.75$. Step 2: Multiply: $0.75 \times 96 = 72$. Answer: 72 (Option 4). 5. Problem: Calculate 5% of 80. Step 1: Convert 5% to decimal: $0.05$. Step 2: Multiply: $0.05 \times 80 = 4$. Answer: 4 (Option 1).