Initially you stood r=30 m from a point source in an open field. You walked a distance and measured the noise level to be β=20 dB less than before. At what distance are you now standing from the point source?

Answer 1

20 Db is power ratio of 10^2 = 100
power at R = (power at 30 ) (1/100)
( 30/R)*2
1/100 = 900/R^2
R^2 = 90000
R = 300