ABC26GN2079 · Logarithms

Subject: General Aptitude · Chapter: Logarithms · Exam: 2011 · Marks: · Difficulty:

If $\log x-5 \log 3=-2$, then $x$ equals
(a)0.8
(b)0.81
(c)1.25
(d)2.43
Answer
Answer (as printed): D
Explanation
$\log x-5 \log 3=-2 \Rightarrow \log x-\log 3^{5}=-2$ $$\Rightarrow \log \left(\frac{x}{3^{5}}\right)=-2 \Rightarrow \frac{x}{243}=10^{-2}=\frac{1}{100} \Rightarrow x=\frac{243}{100}=2.43$$

Explanation as extracted from the printed page; notation may be imperfect.

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