The speed of a boat in still water is 18 km/hr. It takes twice as long to go upstream to a point as to return downstream to the starting point. What is the speed of the current.

a. 12 km/hr
b. 10 km/hr
c. 8 km/hr
d. 6 km/hr
e. 4 km/hr

• upstream = u-v; the speed of boat in still water is u = 18
  = 18-x the speed of the current is v = x
  downstream =u+v;
  18+x
  the above solution 2*upstream = downstream
  2*(18-x)=18+x
  x=6kmph
• 10 years agoHelpfull: Yes(0) No(0)
• Let man's upstream rate be x kmph
  therefore downstream rate = 2x kmph
  still water speed = (x+2x)/2
  18=(x+2x)/2
  x=12.
  speed of current = 24-12/2 = 6kmph
• 6 years agoHelpfull: Yes(0) No(0)