An organic solution is cooled from $121\backslash$deg C to $82\backslash$deg C at a flow rate of $1\mathrm{.}9$ tons$/$min$.$ cooling waterIt flows inside the tubes with a flow rate of $3166$ tons$/$min at $27\backslash$deg C$.$ There are a total of $160$ tubes in the heat exchanger and the tubes are placed in a $1$ in $14$ BWG $($di $=21\mathrm{.}2$ mm$,$ do $=25\mathrm{.}4$ mm$,$ xw $=2\mathrm{.}1$ mm$),$ p $=1^1/4$ in square arrangement and the distance between obstacles is $31\mathrm{.}8$ mm$.$ The shell material is mild steel and the tube material is $304$ stainless steel. Cph$=$ Cpc$=4185$ J$/$kg $\backslash$deg C and the shell inner diameter is $2\mathrm{.}42$ m$.$ a$)(1-2)$ type heat exchanger,b$)$ Calculate for $(2-4)$ type heat exchanger.Note: Take the physicochemical properties of the organic solution as the same as those of water and assume $/$w$=1$