1. The problem statement, all variables and given/known data A person is a certain distance away from a plane with three equally noisy engines at 120 dB. What is the sound intensity if two of the engines are shut off? 2. Relevant equations B (in dB) = log I/Io 3. The attempt at a solution using this equation: 120 dB = 10 log I/Io 10^12 = 10 log (I/10^-12 W/m2) I = (10^12)(10^-12) I = 1 W/m2 So, intensity for three engines is 1 W/m2. If two engines turned off, then I'm pretty sure you don't divide the answer by three to get 0.33 W/m2 per engine because the answer is 116. I can't figure out what I'm doing wrong.