Work carefully with radicals and decimals: Given √5 = 2.24, evaluate (3√5) / (2√5 − 0.48) by simplifying numerator and denominator step by step.

Difficulty: Easy

Correct Answer: 1.68

Explanation:


Introduction / Context:
This problem combines radicals with decimals. The key is to simplify the numerator and the denominator separately using the provided value for √5, and then perform a clean division. Such steps reinforce operational fluency with expressions containing roots and constants.


Given Data / Assumptions:

  • √5 = 2.24 (use as given).
  • Expression: (3√5) / (2√5 − 0.48).


Concept / Approach:
First compute the numerator 3√5 and the linear combination in the denominator 2√5 − 0.48 by substituting √5 = 2.24. Once both are numeric, divide to get the final value. Keep exact steps to avoid decimal slips.


Step-by-Step Solution:

Numerator: 3√5 = 3 × 2.24 = 6.72.Denominator: 2√5 − 0.48 = 2 × 2.24 − 0.48 = 4.48 − 0.48 = 4.00.Compute the quotient: 6.72 / 4.00 = 1.68.


Verification / Alternative check:

Because the denominator simplifies to a neat integer (4), mental division confirms 1.68 exactly without rounding.


Why Other Options Are Wrong:

  • 0.168: Off by a factor of 10.
  • 16.8 and 168: Off by factors of 10 and 100; these ignore the small denominator correction.


Common Pitfalls:

  • Mistaking 2√5 − 0.48 as 2(√5 − 0.48) and distributing incorrectly.
  • Arithmetic slip when subtracting 0.48 from 4.48.


Final Answer:

1.68

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