Simplification and Approximation Questions

Multiple choice
  1. 19450

  2. 19435

  3. 20450

  4. 19950

  5. 18650

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Calculate: 16.2% of 986 ≈ 0.162 × 986 ≈ 159.7. Then 12.8% of 963 ≈ 0.128 × 963 ≈ 123.3. Multiply: 159.7 × 123.3 ≈ 19686. The closest option is 19435 (Option B). The approximation accounts for rounding in intermediate steps.

Multiple choice
  1. 4100

  2. 4200

  3. 4600

  4. 4400

  5. 4000

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Approximate: (38.9)² ÷ 12.95 × 29 = ? - 795. 38.9² ≈ 1510. Then 1510 ÷ 13 ≈ 116. Then 116 × 29 ≈ 3364. So ? ≈ 3364 + 795 = 4159. Among options, 4200 (B) is closest. Option A is too low. Option C is too high. Option D is too high. Option E is too low.

Multiple choice
  1. 1670

  2. 1700

  3. 1650

  4. 1750

  5. 1800

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Use difference of squares: a² - b² = (a+b)(a-b). (97.1)² - (87.2)² = (97.1+87.2)(97.1-87.2) = (184.3)(9.9) ≈ 1824.6. Then subtract (13.01)² ≈ 169.2, giving ≈ 1655.4. Rounding to nearest 50 gives 1670. Option A is correct. Option B is slightly high. Option C is too low. Option D is too high. Option E is much too high.

Multiple choice
  1. 96850

  2. 90770

  3. 98700

  4. 89800

  5. 100000

Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Approximating: 20300 ≈ 20000, 36.14 ≈ 36, 176.120 ≈ 176, 38.72 ≈ 39. So: (20000/36)×176 ≈ 555.56×176 ≈ 97778. Then 97778 - 39 ≈ 97739, which rounds to approximately 100000. The exact calculation: 20300÷36.14 × 176.120 - 38.72 ≈ 561.8×176.12 - 38.72 ≈ 98963 - 38.72 ≈ 98924, closest to 100000 among options.