[SOLVED] System of equations 1. The problem statement, all variables and given/known data Use a system of equations to solve the following problems: (a.) A boat took 1 hour 50 minutes to go 55 miles downstream and 3 hours 40 minutes to return. Find the rate of the current. (b.) A boat travels 60 miles downstream in the same time it takes to go 36 miles upstream. The speed of the boat is 15 mi/h greater than the speed of the current. Find the speed of the current. (c.) A boat travels 12 miles downstream in 1.5 hours. On the return trip the boat travels the same distance upstream in 2 hours. Find the rate of the boat in still water and the rate of the current. 2. Relevant equations distance = rate * time 3. The attempt at a solution Here's a lame-brained attempt to solve problem (b) ... [tex]d=rt[/tex] [tex]r=r_b + r_w[/tex] [tex]d = (r_b + r_w)t[/tex] [tex]r_b = 15 + r_w[/tex] [tex]d = (15 + 2r_w)t[/tex] ??? ... I can't figure out how to solve any of these. Could you at least help me to set them up correctly? Thank you.