In a kilometer race, If A gives B a 40m start, A wins by 19sec. But if A gives B a 30 sec start, B wins by 40 m. Find the time taken by B to run 5,000m?

• Let A travells 1000m in x sec and b in (x+19)sec
  Therefore, speed of B is 1000/(x+19)
  B travel 960m in x sec from here equation of speed=960/x
  speed of B is constant so boht the speed equation for B are equal
  960/x = 1000/(x+19)
  On solving we get x=456sec
  Time taken by B for 5000m : 5000/(960/456)=2375
  The ans will be 2375
• 8 years agoHelpfull: Yes(9) No(5)
• If A takes x seconds and B takes y seconds to run 1km, then:
  x+19=
  960y
  1000
  and
  960x
  1000
  +30=y
  ⇒ y=150 sec and x=125 sec
  Answer =
  150
  1000
  ×5000
  = 750 sec
• 8 years agoHelpfull: Yes(5) No(0)
• let the speeds of A and B be v1 and v2 respectively
  from 1st condition,
  v1=1000/t
  v2=960/(t+19) [since B starts the race from the point 40m ahead of A]
  from the second condition,
  v1=960/t2
  v2=1000/(t2+30)[since B gets 30 sec headstart and reaches 1000m when A is 40m behind]
  solving for v2 we get t2=132.24 sec
  thus v2=1000/162.24
  therefore for 5000m t3=811 sec
  
• 8 years agoHelpfull: Yes(3) No(2)
• if A takes x seconds and B take Y seconds for 1km race
  
  so from 1st meaning x+19=960y/1000 ->y=150 seconds
  
  from 2nd statement y-30=960x/1000 -> x=125 seconds
  
  now the qus is How much time taken by B to cover 5000m
  
  so 150/1000*5000=750 sec
• 8 years agoHelpfull: Yes(2) No(0)
• 375sec
  let x be speed of a, y be speed of b
  x=1000/t, y=960/t+19
  also
  x=960/g, y=1000/t+30
  solving 1000/t=960/g
  960/t+19=1000/30+g
  solving these we get t =125
  hence y=960/125+19
  t for next ans=5000*144/960
• 8 years agoHelpfull: Yes(1) No(2)
• 1.A gives B a 40metre start then B runs 960m in T secs and A runs 1000m in T-19 secs.
  
  2.A gives B a 30 second start then B runs 1000m in t secs and A runs 960m in (t-30) secs.
  
  
  Assuming speed of A=X and B=Y
  
  Then,
  X = 960 ÷ T = 1000 ÷ t,
  960t = 1000T
  
  
  Y = 1000 ÷ (T - 19) = 960 ÷ (t - 30)
  1000t - 30000 = 960T - 18240
  Then 40t = -40T + 11760,
  t = -T + 294.
  Substituting for t in 960t = 1000T gives
  -960T + 282240 = 1000T
  1960T = 282240
  T = 144
  B 's speed is 960 ÷ T = 960 ÷ 144 = 6.67 metres per second.
  to run 5000 metres the time taken is 5000 ÷ 6.67 = 750 seconds
• 8 years agoHelpfull: Yes(1) No(0)
• If A takes x seconds and B takes y seconds to run 1km, then:
  x+19=
  960y
  1000
  and
  960x
  1000
  +30=y
  ⇒ y=150 sec and x=125 sec
  Answer =
  150
  1000
  ×5000
  = 750 sec
• 6 years agoHelpfull: Yes(1) No(0)
• Please tell the correct answer
• 8 years agoHelpfull: Yes(0) No(0)
• 750
  answer
  
• 8 years agoHelpfull: Yes(0) No(0)
• ravi in your ans it is coming p=7 and p=3 ....your ans is wrong also
  
• 8 years agoHelpfull: Yes(0) No(0)
• I am getting 835.22sec
• 8 years agoHelpfull: Yes(0) No(0)
• No need of first statement because in the second statement all the required data is given
  By considering the second statement,
  v=d/t=>30=40/t
  t=4/3
  For 5000 mts, t=d/v=5000/(4/3)=3250
  
• 8 years agoHelpfull: Yes(0) No(0)
• If A takes x seconds and B takes y seconds to run 1km, then:
  x+19=
  960y
  1000
  and
  960x
  1000
  +30=y
  ⇒ y=150 sec and x=125 sec
  Answer =
  150
  1000
  ×5000
  = 750 sec
• 6 years agoHelpfull: Yes(0) No(0)
• 1. A can run 1000 m in T-19 sec
  and B can run 960 m (1000-40) in T sec .
  2 . A can run 960 m in t-30 sec
  and B can run 1000 m in t sec .
  then ....< speed =distance /time > .
  speed=1000/T-19=960/t-30--------eqn.1
  speed=960/T=1000/t---------------eqn.2
  
  therefore,by solving both
  eqn 1 & 2
  T=144
  t=150.
  
  therfore ,1000-----150
  5000------? 5000*150/1000= 750..
  and
  if , 960------144
  5000------? 5000*144/960= 750...
• 5 years agoHelpfull: Yes(0) No(0)