if raghv travel at 15kmph he reaches office at 10am.if he travels at 10kmph he reaches office at 10:30 am .atwhat speed
should he travel so that he reaches office at 10:15.(assume he leave home at same time and takes the same route)

• Time taken when speed 15km/hr = D/15
  Time taken when speed 10 km/hr= D/10
  therefore diff = d/10-d/15=30/60
  therefore d=15
  let new speed be s
  15/10-15/s=15/60( time difference)
  this comes to s= 12 ans
  
• 10 years agoHelpfull: Yes(26) No(0)
• 15 Kmph = 10 am
  10 Kmph = 10:30 am
  
  so, 5 kmph = 30 min
  
  2.5 Kmph = 15 min
  
  So add, 2.5 Kmph speed to original speed = 12.5 Kmph speed
  
  
• 10 years agoHelpfull: Yes(22) No(14)
• let assume he started at 9:00am then in one hour he travels 15 km 15=15*1
  and in 3/2hour he again travels 15 km 15=10*(3/2)
  so d=s*t
  15=x*(3/4)
  x=12km/h
  
• 10 years agoHelpfull: Yes(7) No(1)
• avg speed=2*15*10/25=12 km/hr
  
• 10 years agoHelpfull: Yes(7) No(0)
• 12 kmph
  x/10-x/15=2
  x=60
  so 60/10=6hrs
  so starts at 8.00AM
  for 1.00AM we can calculate as 60/5=12kmph
• 10 years agoHelpfull: Yes(3) No(0)
• ans : 12kmph.
  
  
• 10 years agoHelpfull: Yes(2) No(0)
• let the time at which the man started for office is at 9 am.
  when he reached office at 10 am at 15km/hr clearly says that the total distance is 15km.
  when he travelled at 10km/hr he reached at 1030 am.....
  so to get the speed for which he will reach at 10:15 am
  s=d/t
  =15/1.25 or 15/5/4
  =12 km/hr
• 10 years agoHelpfull: Yes(1) No(0)
• 12.66 kmph
• 10 years agoHelpfull: Yes(0) No(1)
• 10-15=5km/hr
  5km/hr=30min extra
  2.5km/hr=15min
  10+2.5=12.5km/hr speed to reach at 10.15am
• 10 years agoHelpfull: Yes(0) No(2)
• let assume distance is 15 km
  with 15km/hr it takes 1 hr
  with 10km/hr it takes 3/2 hr
  so to complete d distance in 5/4 hr
  it becomes 12km/hr
• 9 years agoHelpfull: Yes(0) No(0)