A classroom measuring $10m7\mathrm{.}5m3m$ has a capacity of $35$ seats with a reverberation time of $1\mathrm{.}5$ seconds. $($a$)$ If the classroom is fully occupied $($Stonang $0\mathrm{.}35m^2-$Sabin$),$ determine the reverberation time under these conditions, and $($b$)$ if under conditions such as $($a$)$ it is desired to meet the reverberation time requirement of $0\mathrm{.}6$ seconds, determine the acoustic absorption area that must be added to the classroom.