I am struggling with understanding the difference between decibels and intensity. I know that intensity can be measure in decibels but they are not always the same thing. I have a problem where there is a police car 200 meters from an accident runing sirens at 80 decibels. I am asked to find how many decibels higher the sound intensity will be when the police car is only 50 meters away. Then I am asked to find how many cars are needed to match the sound of a rock concert (120 dB). I tried using (I1/I2)=(R2/R1)^2 but I ended up getting 1200 dB which I knew could not be correct. What should I do?