1. The problem statement, all variables and given/known data At a rock concert the fans in the front row are bombarded with 113 dB of sound. How many rock bands playing simultaneously at this level would be required to reach or exceed the pain threshold (120 dB)? The answer has to be an integer. (Fractional rock bands don't exist ...) 2. Relevant equations Db = 10log(I/I_ref) 3. The attempt at a solution I started by finding the intensity (in W/m^2) of the band using I_ref of 1E-12 W/m^2. That number was 0.1995 Then I found the intensity that would be needed to produce 120 decibels, which was 5 times greater, but that answer was marked wrong. It makes sense to me though, and when I check how many decibels 5x.01995 W/m^2 would produce, I get 120. Where did I go wrong on this one? Thanks!