Solved UPSC CDS/OTA Question
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Q · LogarithmMedium · 45s
If log₃ = .4771,
TopicLogarithm
Question Typemultiple choice
DifficultyMedium
Marking+1 / −0.33
Test Duration30 min
Step-by-Step Solution
The complete worked solution.
Every step explained — no skipped algebra.
2log(81/100) × 2/3log(27/10) ÷ log₉
= 2[log₃₄ – log₁₀₀] × 2/3[(log₃₃ – log₁₀)] ÷ 2log₃
= 2[log₃₄ – log₁₀₀] × 2/3 [(3log₃ – 1) ÷ 2log₃
Substitute log₃ = 0.477 ⇒ –0.0552.
Final Answer: Option B — –0.0552