Robert is travelling on his cycle and has calculated to reach point A at 2 P.M. if he travels at 10 kmph, he will reach there at 12 noon if he travels at 15 kmph. At what speed must he travel to reach A at 1 P.M.?
1) 8 kmph
2) 11 kmph
3) 12 kmph
4) 14 kmph

• lets assume total distance X km...and total time Y hours.
  by travelling with 10 km speed...speed time relation wiil be X/10=Y
  by travelling with 15 km speed ...speed time relation will be X/15=y-2
  X=10Y;
  substitue in 2 nd equation u will get total distance 60km...so reverse direction
  to reach 60 km distance by 10 km speed it took 6 hours ...so Robert started his journey at 8AM
  if he want travel 60 km in 5 hours time (from 8AM to 1PM) he maintain speed 60/5..i.e. 12kmph
• 9 years agoHelpfull: Yes(14) No(1)
• Time= 2pm to 12noon is 2 hrs
  So first calculate the distance...let the distance be d
  d/10-d/15=2; d=60km
  Now considering first part Time taken to complete 60 km at 10kmph = 60/10= 6 hrs
  Therefore he started his journey 6 hrs before 2 p.m i.e. 8a.m.
  Now from 8a.m to 1 p.m is 5 hrs and distance is same 60km.
  Speed= distance/time=60km/5hr= 12kmph
• 8 years agoHelpfull: Yes(6) No(0)
• http://www.indiabix.com/aptitude/time-and-distance/discussion-441
• 9 years agoHelpfull: Yes(1) No(0)
• Let the distance travelled by x km.
  
  Then, x - x = 2
  10 15
  3x - 2x = 60
  
  x = 60 km.
  
  Time taken to travel 60 km at 10 km/hr = 60 hrs = 6 hrs.
  10
  So, Robert started 6 hours before 2 P.M. i.e., at 8 A.M.
  
  Required speed = 60 kmph. = 12 kmph
• 8 years agoHelpfull: Yes(1) No(0)
• plz ..provide the solutiion....tmrw i have a xam...ayshu.530@gmail.com
• 10 years agoHelpfull: Yes(0) No(0)
• distance=60
  time=5
  speed=12kmph
  
  
  
• 9 years agoHelpfull: Yes(0) No(1)
• 3) is right answer.
  let he start at x; now at 14 o'clock he reach destination. total time=14-x
  if he cycle with 15kmph he reach at 12; total time=12-x
  equations:140-10x=d
  and 180-15x=d
  comparing we have-> x=8 and total time is 5hr. Also d=60
  now speed=60/5 = 12kmph
• 8 years agoHelpfull: Yes(0) No(0)
• 2 speeds are given, so we can use avg speed formula
  2xy/x+y= (2*10*15)/10+15=(2*10*15)/25= 12
• 7 years agoHelpfull: Yes(0) No(0)