A 1/4-in steel plate having a thermal conductivity of 25 Btu/h ft F is exposed

Question:

A 1/4-in steel plate having a thermal conductivity of 25 Btu/h · ft · ºF is exposed to a radiant heat flux of 1500 Btu/h · ft2 in a vacuum space where the convection heat transfer is negligible. Assuming that the surface temperature of the steel exposed to the radiant energy is maintained at 100ºF, what will be the other surface temperature if all the radiant energy striking the plate is transferred through the plate by conduction?