A hydrocarbon oil of density $950$ kg$/$m$^3$ and specific heat capacity $2\mathrm{.}5$ kJ$/$kg K is cooled in a heat exchanger from $363$ to $313$ K by water flowing countercurrently. The temperature of the water rises from $293$ to $323$ K$.$ If the flowrate of the hydrocarbon is $0\mathrm{.}56$ kg$/$s$,$ what is the required flowrate of water?

After plant modifications, the heat exchanger is incorrectly connected so that the two streams are in co$-$current flow. What are the new outlet temperatures of hydrocarbon and water, if the overall heat transfer coefficient is unchanged?