Car A leaves city C at 5pm and is driven at a speed of 40 kmph. Two hours later another car leaves city C and is driven in same direction as car A. In how much time car B be 9 km ahead of car A if the speed of car B is 60 kmph.

• car A speed = 40 kmph, car B speed 60 kmph
  relative speed=60-40=20 kmph(same direction)
  when car B stated A has already covered 40*2=80m distance
  time required for two car to be at same position = 80/20=4hr
  additional distance is 9 min
  to additional time= (9/20)*60=27 min
  answer is 4grs 27 min
• 11 years agoHelpfull: Yes(69) No(5)
• after 4hrs they will meet together.From that there should be distance of 9kms b/w them. Hence the time=distance/relative speed. t=9/20=27min.So the total time taken is 4hrs+27min=4hrs27mins.
• 11 years agoHelpfull: Yes(32) No(2)
• Sorry guys ans will be (4 hrs 27 mins)
• 11 years agoHelpfull: Yes(9) No(5)
• after 4hrs they will meet together.From that there should be distance of 9kms b/w them. Hence the time=distance/relative speed. t=9/20=27min.So the total time taken is 4hrs+27min=4hrs27mins.
• 11 years agoHelpfull: Yes(9) No(1)
• relative speed is 20.
  then in 2 hr dist covered by a 80.
  time taken by b to cover 80 is 80/60=1hr 20 min
  and to cover 9 km more =9/20=27min
  total time=1hr 47min
  
• 11 years agoHelpfull: Yes(5) No(10)
• a and b meet after 80/20=4 hour + 9km/20=27min ...total 4hr 27min
• 11 years agoHelpfull: Yes(5) No(0)
• relative speed is 20
  and when b started A is 80KM ahead
  time required for b to be ahead of A by 9Km=(80+9)/20
  =4 hrs 27 mins
• 11 years agoHelpfull: Yes(3) No(3)
• can anyone xplain
  
• 11 years agoHelpfull: Yes(2) No(0)
• 1 hour 29 mins
  
• 11 years agoHelpfull: Yes(1) No(7)
• 21 hrs b started 2 hrs later, so after 21 hrs the difference will be 9 km between them
• 11 years agoHelpfull: Yes(1) No(5)
• 4 hours and 27 minutes later !!!
• 11 years agoHelpfull: Yes(1) No(0)
• Relative speed 60 - 40 20 kmphInitial gap as car B leaves after 2 hours 40 x 2 80 kmsCar B should be 9 km ahead of the A at a required time so it must be 89 km awayTime 89 20 445 hrs or 267 mins
• 10 years agoHelpfull: Yes(1) No(1)
• first we will calculate the distance travel by car A in two hours i.e. 80 km. now their relative speed is 20 kmph and distance will be 89 km. so car B will be ahead of car A in (89/20) = 4.45 hrs.
• 9 years agoHelpfull: Yes(1) No(0)
• ans is 4hr 15 min
• 11 years agoHelpfull: Yes(0) No(2)
• after car a and b starts they meet at a point 240km from the start(40kmph*6=60kmph*4).so car b takes 4hrs to meet a.so to travel 9km ahead we take the relative vel..ie.(60-40)kmph..so time taken is (9/20)*60=0.47*60=27min..so b take 4hrs 27min
• 11 years agoHelpfull: Yes(0) No(0)
• .15h
  9/60=.15
  
• 11 years agoHelpfull: Yes(0) No(1)
• Let after t time two cars will met.
  So A will travel distance of 40t with 40kmph
  B will travel the distance of 60t with 60kmph
  And also A is ahead 80 km(40*2=80) from B
  so 60t - 40t = 80 => t = 4hrs
  and time taken by B to cover 9kms more is 9/60 = 9mins
  So the total time is 4 hours 9 mins
• 11 years agoHelpfull: Yes(0) No(1)
• car A speed = 40 kmph,
  car B speed 60 kmph
  relative speed=60-40=20 kmph(same direction)
  when car B stated A has already covered 40*2=80m distance
  two cars are meet together ::::80/20=4hr
  additional distance is 9 min
  to additional time= (9/20)*60=27 min
  so correct answer = 4hrs 27 min
  
• 9 years agoHelpfull: Yes(0) No(0)
• twice distance over so 2*40 now relative speed is 20
  t=80/20=4 hrs
  now given 20 km in 1 hrs
  so in 9 km it will be 9/20 convert in min by 60
  we get 4hrs 27min.
  
  
• 9 years agoHelpfull: Yes(0) No(0)
• A=40kmph
  B=60kmph
  relative speed=60-40=20
  in 2hrs A covered 80km
  time required to meet 2 cars=80/20=4hr
  9 km more in the sense =(9/20)*60=27min
  ==4h27min
• 8 years agoHelpfull: Yes(0) No(0)
• Relative speed of car b=20kmph
  in two hrs distance traveled by car A=50x2=80
  Time taken to reach car A by Car B=80/20=4hrs
  Time taken to travel 9 km extra with respect car A=9/20=27min
  So required time=4hr and 27 minutes
• 6 years agoHelpfull: Yes(0) No(0)