A heavy hydrocarbon oil which has a Cpm $2\mathrm{.}30$ kJ$/$kg$.$K is being cooled in a heat exchanger from $371\mathrm{.}9$ K t $349\mathrm{.}7$ K and flows inside the tube at a rate of $3630$ kg$/$h$.$ A flow of $1450$ kg water$/$h enters at $288\mathrm{.}6$K for cooling and flows outside the tube.

Calculate the water outlet temperature and heat$-$transfer area if the overall Ui $340$ W$/$mK and the streams are counter$-$current.

b$.$ Repeat for parallel flow