Approximation with near-integers: Evaluate 4182.395 ÷ 20.886 and choose the closest value among the options (use sensible rounding/estimation where helpful).

Difficulty: Easy

Correct Answer: 200

Explanation:


Introduction / Context:
This is a division-based approximation problem. The decimal numbers 4182.395 and 20.886 are close to round figures, so we can estimate quickly without a calculator. The goal is to convert to a simple mental-math division while keeping the ratio nearly the same.


Given Data / Assumptions:

  • Numerator = 4182.395 (close to 4182 or 4200)
  • Denominator = 20.886 (close to 21)
  • We must select the closest option to the exact quotient.


Concept / Approach:
When both numbers are near convenient round numbers, approximate each minimally so the ratio stays stable. Use 4182/20.9 or 4182/21 as quick proxies. Always sanity-check by multiplying a candidate answer by the divisor to see if we return near the dividend.


Step-by-Step Solution:

Use a tight rounding: 4182.395 ≈ 4182; 20.886 ≈ 20.9Compute 4182 ÷ 20.9 ≈ 200.1 (since 20.9 * 200 = 4180)Using the exact values gives about 200.25, still ≈ 200


Verification / Alternative check:
Multiply 200 * 20.886 = 4177.2 (slightly low). Adding one more unit (201) gives ≈ 4198.9 (slightly high). The true answer lies near 200.2, so 200 is the closest choice.


Why Other Options Are Wrong:

  • 250: 250 * 20.886 ≈ 5221, far too large.
  • 300: 300 * 20.886 ≈ 6266, much too large.
  • 150: 150 * 20.886 ≈ 3133, too small.
  • 180: 180 * 20.886 ≈ 3759, still low.


Common Pitfalls:
Over-rounding both numbers in the same direction can distort the ratio. Keep the rounding tight and check by back-multiplying the candidate answer.


Final Answer:
200

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