If log ₁₀ x+log ₁₀ 5=2, then x equals · ABC26GN2058

Subject: General Aptitude · Chapter: Logarithms

If $\log _{10} x+\log _{10} 5=2$, then $x$ equals

(a)15

(b)20

(c)25

(d)100

Answer

Answer (as printed): B

Explanation

$$\begin{aligned} \log _{10} x+\log _{10} 5=2 & \Rightarrow \log _{10} 5 x=2 \\ & \Rightarrow 5 x=10^{2}=100 \Rightarrow x=20 . \end{aligned}$$

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

Study loop for Logarithms