) A person walks on a plain land at 4 km/hr and up the slope at 3 km/hr and comes
down at 6 km/hr and walks on the plain land again at 4 km/hr. if he started at 3:00
pm and comes back at 9:00 pm. What is the one way distance?

• Tricky question, see this solution for good concept -
  
  Man will go up and down with 3km/hr and 6km/hr respectively,
  so av = (2*3*6)/(3+6) = 4km/hr
  so we get to know that overall journey is traveled with 4km/hr actually, that was the trick here.
  and now
  total distance covered = speed*time = 4*6 = 24 km
  so one way distance = 12km
• 11 years agoHelpfull: Yes(11) No(0)
• when he was going on the way his speed was 3km/hr & 4 k/hr
  find averge speed of that you will get=a=24/7
  when he was coming back his speed was 6km/hr & 4 km/hr
  find its average=b=24/5
  now we have got two average speeds a & b
  now find averge of a & b
  we will get averge of all the speeds ie v=4 km/hr
  we know the time 6hr (ie from 3pm to 9 pm)
  now just apply the v=d/t
  d=v*t
  d=4*6=24km(two way distance)
  therefore one way distance=12km
  
• 12 years agoHelpfull: Yes(4) No(0)
• The total distace he walked 24 Kilometer
  the person start walking in plain land at 4km/hr and after 1.5 hour he got upslope and walked 3km/hr after 2 hours he stop and start walking down slope at 6km/hr and after 1 hour he reached at plain land and after 1.5 hour he reached at the position from where he started thats mean he did total 6 hours journey and total distance is 24 Kilometer
• 12 years agoHelpfull: Yes(2) No(2)
• let us consider that he takes equal time for walking on the plain road, then on uphill, then downhill and finally on the plain road. So time required for each portion = 6/4
  
  distance = speed * time
  
  4*6/4 + 3*(6/4) + 6*(6/4) + 4*(6/4) = 25.5
  
  distance of one way = 25.5 /2 = 12.75
• 12 years agoHelpfull: Yes(1) No(4)
• i didn't get the answer
  can any1 tell me......????
  
• 11 years agoHelpfull: Yes(0) No(1)