two trains having length L1 & L2 and having velocities V1 & V2 cross each other in t units of time when moving in opposite direction and take time T to cross each other while moving in same direction. if the ratio of T to t (T:t) is 11 then what will be value of V1/V2 ?
a) 5L1/6L2 b) 6L1/5L2 C) 1.2 d) 11L1/L2

• T/t=11
  Then v1+v2 / v1-v2 = 11
  V1/V2=1.2
• 7 years agoHelpfull: Yes(15) No(1)
• option c) 1.2
  T=L1+L2/V1-V2
  t=L1+L2/V1=V2
  therefore, V1+V2/V1-V2 =11
  
• 7 years agoHelpfull: Yes(11) No(3)
• v1+v2=1/t--------(1)
  v1-v2=1/T---------(2) (since,speed and time are inversely related)
  from (1) and (2)
  (v1+v2)/(v1-v2)=T/t
  (v1+v2)/(v1-v2)=11----(given)
  on cross multiplying, we get
  v1+v2= 11(v1-v2)
  Taking v1 on same side and v2 on other side, we get
  12v2=10v1;
  thus, v1/v2=1.2 (answer) option (C)
• 7 years agoHelpfull: Yes(6) No(0)
• T=(L1+L2)/(V1-V2) for same dir. Movement
  t=(L1+L2)/(V1+V2) for opposite
• 7 years agoHelpfull: Yes(4) No(1)
• According to the question
  V1 +V2=L1+L2/t
  V1-V2= L1+L2/T
  ON SOLVING
  V1-V2/V1+V2 =1/11
  V1/V2=1.2
  
• 7 years agoHelpfull: Yes(2) No(1)
• In case , moving in same direction we can give the relationship as follows
  L1+L2=(V1-V2)(T)--------(1)
  In case , moving in opposite direction we can give the relationship as follows
  L1+L2=(V1+V2)(t)-------(2)
  by solving 1 & 2 and keeping T:t=11,
  we get V1/V2=6L1/L2
  
• 7 years agoHelpfull: Yes(0) No(8)
• T=(L1+L2)/(V1-v2)..(1)
  t=(L1+L2)/(V1+v2)..(2)
  (1)/(2)....
  11=(v1+v2)/(v1-v2)
  V1/V2=6L1/5l2(as v directly proportional to length)
  
  
• 7 years agoHelpfull: Yes(0) No(7)
• ((L1+L2)/((V1-V2))(/(L1+L2)/(V1+V2))=11=>1.3
  so ans is c
• 7 years agoHelpfull: Yes(0) No(2)