Answer
$E = 71~MeV$
Work Step by Step
We will use a single equation to find the energy in the apartment:
$E = (photon~energy)(number~of~photons)(volume)$
$E = (h~f)(number~of~photons)(volume)$
$E = (6.626\times 10^{-34}~J~s)~(160\times 10^9~Hz)(450~cm^{-3})(10^6~cm^3/m^3)(95~m^2)(2.5~m)$
$E = 1.133046\times 10^{-11}~J$
$E = (1.133046\times 10^{-11}~J)(\frac{1~eV}{1.6\times 10^{-19}~J})$
$E = 7.1\times 10^7~eV$
$E = 71~MeV$
