Draw the temperature distribution for a parallel-flow double-pipe exchanger. U = 800 W/m^{2}·°C, A = 0.5 m^{2}; T_{h,i} = 50 °C, T_{h,o} = 40 °C, T_{c,i} = 25 °C, T_{c,o} = 35 °C. Find the heat transfer. (answer: heat transfer in kW)