math word problem

Question

A motorboat travels 235km in 5 hours going upstream. It travels 335km 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

235= 5(r-c)

47 = r-c

335 = 5(r+c)

67 = r+c

2c=20

c = 10 km/h current speed

r = 57 kmh boat speed

5(67) = 335

5(47) = 235