Question 954052
r=15
c=unknown, the current
r+c=upstream speed
r-c=downstream speed
T=total time of {{{6&3/4}}} hours
d=45


__________________speed_________time__________distance
upstream__________r-c____________d/(r-c)_____________d
downstrm__________r+c____________d/(r+c)_____________d
Total_____________________________T


Uniform Rates Rule for Travel, RT=D


The basic equation setup all in symbolic form:   {{{highlight(d/(r-c)+d/(r+c)=T)}}}
Solve for c.