Question $4(5$ points$)$

What is the total friction loss of $750$ gpm flowing through $500$ ft of $6$ in Sch $40$ pipe with three swing check valves in a manual wet standpipe system?

a$)12\mathrm{.}6$

b$)14\mathrm{.}8$

c$)13\mathrm{.}7$

d$)11\mathrm{.}7$