Answer
Ratio = 25
Work Step by Step
Given the decibel equation $B = 10 \log \frac{I}{I_{0}}$
with $I_{0} = 10^{-12} \frac{W}{m^2}$
Given the decibel level of a Rock concert at $B = 120 dB$
Find the sound intensity
$120 = 10 \log \frac{I}{10^{-12}}$
$12= \log \frac{I}{10^{-12}}$
$10^12 = \frac{I}{10^{-12}}$
$I = 1 \frac{W}{m^2}$
Given the decibel level of a Rock concert at $B = 106 dB$
Find the sound intensity
$106 = 10 \log \frac{I}{10^{-12}}$
$10.6= \log \frac{I}{10^{-12}}$
$10^{10.6} = \frac{I}{10^{-12}}$
$I = 10^{-1.4} \frac{W}{m^2}$
Ratio of intensity
$R = \frac{1}{10^{-1.4}}$ = $25$
Thus the ratio is 25