It is desired to cool a fluid from $75\backslash$deg C to $50\backslash$deg C flowing through the shell of an I.C$.(1$ pass through shell and $2$ through tubes$).$ The equipment has $120$ tubes, which have: an external diameter, Do $=0\mathrm{.}0254$ m$,$ internal diameter, Di $=0\mathrm{.}02$ m and a length of $3$ m$.$ The cooling medium is water, which flows inside tubes at a rate of $10$ kg$/$s$.$ The cooling water enters at $30\backslash$deg C and its temperature is estimated to increase to $42\backslash$deg C$.$