$10,000$ lb$/$h of benzene is to be heated from $60$F to $120$F by heat exchange with an aniline stream that will be cooled from $150$F to $100$F$.$ A number of $16$ft hairpins consisting of $2$in$.$ by $1\mathrm{.}25$in$.$ schedule $40$ stainless steel pipe $($type $316,$ k $=9\mathrm{.}4$ Btu$/$h $$ ft $$ F$)$ are available and will be used for this ser vice. Assuming that the benzene flows in the inner pipe, how many hairpins will be required? Redo this question with information given in the picture please