An AV Room is separated from the hallway by a painted 6-inch concrete hollow block wall with plaster on both side. The room has to have an ambient sound of 30 dB. What is the maximum sound level (in dB) from the hallway that will make this condition possible? Show the equation used and step by step solution.

An AV Room is separated from the hallway by a painted 6-inch concrete hollow block wall with plaster on both side. The room has to have an ambient sound of 30 dB. What is the maximum sound level (in dB) from the hallway that will make this condition possible? Show the equation used and step by step solution.