Algebra help with question

Question

A motorboat travels 188 kilometers in 4 hours going upstream. It travels 300 kilometers going downstream in the same amount of time. What is the rate of the boat in still water and what Is the rate of the current.

Answer 1

distance = rate of speed times time

d=rt

d/r = t

188/(r-c) = 300/(r+c) = 4

4r-4c = 188

4r+4c = 300

8r = 488

r=488/8 = 61 kmh = the motorboat's still water speed

r-c=188/4=47

c=61-47 = 14 kmh = current speed

188/47 = 300/75 = 4 hours