Heat is flowing in steady state from temperature 100oC to temperature 0oC  through a rod of length l, cross sectional area A and thermal conductivity K at a rate Q. When another rod of length 2l, cross-sectional area A and thermal conductivity K/2 is joined end to end to the above rod to make a composite rod of length 3l whose ends are maintained at 100oC and 0oC, rate of heat conduction at steady state is