Solve the following mathematics problems: 1. Round 2,748,595 to the nearest 10,000. 2. Multiply 0.0409 by 0.0021 in standard form. 3. A student spent 1/4 of her money on books and 1/3 on transport. Wh

Here are the solutions to the problems: 3. Write 2,748,595 correct to the nearest 10,000. Step 1: Identify the digit in the ten thousands place. The number is 2,748,595. The digit in the ten thousands place is 4. Step 2: Look at the digit to the right of the ten thousands place. The digit to the right is 8 (in the thousands place). Step 3: Round based on the digit identified in Step 2. Since 8 is 5 or greater, we round up the digit in the ten thousands place. The 4 becomes 5. All digits to the right become zeros. Step 4: Write the rounded number. 2,748,595 ≈ 2,750,000 The correct option is C. C. 2,750,000 4. Find the product of 0.0409 and 0.0021, leaving the answer in standard form. Step 1: Convert each number to standard form (scientific notation). 0.0409 = 4.09 × 10^-2 0.0021 = 2.1 × 10^-3 Step 2: Multiply the numbers in standard form. (4.09 × 10^-2) × (2.1 × 10^-3) Step 3: Multiply the numerical parts and the powers of 10 separately. (4.09 × 2.1) × (10^-2 × 10^-3) 8.589 × 10^(-2) + (-3) 8.589 × 10^-5 The correct option is B. B. 8.589 × 10^-5 5. A student spent (1)/(4) of her money on books and (1)/(3) on transport. What fraction of the money was left? Step 1: Calculate the total fraction of money spent. Fraction spent on books = (1)/(4) Fraction spent on transport = (1)/(3) Total fraction spent = (1)/(4) + (1)/(3) Step 2: Find a common denominator for the fractions and add them. The least common multiple of 4 and 3 is 12. (1)/(4) = (1 × 3)/(4 × 3) = (3)/(12) (1)/(3) = (1 × 4)/(3 × 4) = (4)/(12) Total fraction spent = (3)/(12) + (4)/(12) = (3+4)/(12) = (7)/(12) Step 3: Calculate the fraction of money left. The total money is represented by 1 (or (12)/(12)). Fraction left = 1 - Total fraction spent Fraction left = (12)/(12) - (7)/(12) = (12-7)/(12) = (5)/(12) The correct option is B. B. (5)/(12)$