Please don't copy and paste from chegg or Chatgpt.

A single pressure HRSG with an economizer, boiler, and superheater provides steam at $1250$ psia and $950$F$.$ The BFW enters the HRSG at $274$F$.$ Assuming a pinch point of $80$F$,$ calculate the steam flow rate and stack temperature for an exhaust flow rate of $1,680,000$ lb$/$h$.$ The combustion turbine has a discharge temperature of $960$F$,$ but duct burners add an additional $26\mathrm{.}6$x$10^6$ Btu$/$h$.$