Given log<sub>10</sub>2 = 0.3010 and log<sub>10</sub>3 = 0.4771, evaluate log<sub>5</sub>512.

Aptitude Logarithm Difficulty: Medium
Choose an option
  • A
    3.700
  • B
    3.876
  • C
    3.909
  • D
    4.000

Answer

Correct Answer: 3.876

Explanation

Concept / Approach

  • Use change of base: log5512 = log10512 / log105.

Step-by-step calculationlog10512 = log10(29) = 9 × 0.3010 = 2.709log105 = 1 − log102 = 1 − 0.3010 = 0.6990log5512 = 2.709 / 0.6990 = 3.876 (approx.)

Verification53 = 125 < 512 < 625 = 54 ⇒ answer between 3 and 4, consistent.

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