The human ear can withstand 85 dB for 8 hours before permanent hearing damage occurs. Given that the exposure time is halved for every 3 dB increased over 85 dB, find the safe exposure time for:
I) The cabin of a steam locomotive, 100 dB
II)A rock concert 115 dB
I understand that this is a decay question and that you obtain (0.5)^5*8 for the first one but the answer says that you must also multiply this by 60 to obtain an answer in minutes, which makes no sense to me as to how we are not already working in hours.