Question

sara can row 30km downstream and return in a total of 8 hours.If tge speed of the boat in still water is four times the speed of the current, then the speed of the current is

Answer 1

t = d/v  

15/(v + c) + 15/(v - c) = 8  

15/(5c) + 15/(3c) = 8  

3/c + 5/c = 8  

8/c = 8  

8c = 8  

c = 1 km/hr  

And if 30 km is one way:  

30/(5c) + 30/3c = 8  

6/c + 10/c = 8  

16/c = 8  

c = 2 km/hr

Answer 2

Answer:

c=2km is correct answer.