A & B travelling from X to Y. A starts at 12 pm at a speed of 63m/hr. B at 1:30 pm at a speed of 84m/hr.At what time will B be 34m ahead of A?

• when A starts at 12 pm its covers 63*1.5 = 94.50m distance till 1:30 pm ....
  relative speed of B = 84-63 = 21m /hr ......
  now total distance covered by B is 94.5+34 =128.50 m
  time taken by B to reach 34m ahead of A = 128.50/21 = 6.12 hr
  so time is =1.30 + 6.12 = 7.42 pm
  
  
  
  
  
• 12 years agoHelpfull: Yes(111) No(4)
• at 7:37pm B will be 34m ahead of A
• 12 years agoHelpfull: Yes(19) No(16)
• can u plz explain the solution clearly
• 12 years agoHelpfull: Yes(7) No(7)
• Time taken to overtake A by B = 94.5/21 =4.5 hour
  
  Time taken to cover 34m with relative speed = 34/21 =1.61 hour
  
  So, Total time= 4.5 + 1.61 =6.11 hour
  
  so, At 7:41 B will be 34m ahead of A.
• 12 years agoHelpfull: Yes(7) No(11)
• B starts after 1.5 hours .(as 1:30 PM-12 PM = 1 hr 30 min = 1.5 hrs)
  in that time A will move 63*1.5=94.3 m
  So now at 1:30 PM the current distance between them = 94.5 m AND the relative speed = 84-63=21 m/hr ( As they are moving in same direction ).
  so time taken by B to catch A = (Distance/relative Speed)= 94.5/21= 4.5 hrs .
  Now as per the condition B will move ahead of 34 m.For that B will take more 34/21= 1.6 hrs.
  So the total time taken = 4.5+1.6=6.1 hrs .
  And the time when B will 34 m ahead of A is 7:05 PM
  
• 8 years agoHelpfull: Yes(1) No(0)