Q. In a 100m race, if A gives B a start of 20m then A wins the race by 5 sec. If A gives B a start of 40m the race ends in a dead heat. How long does A takes to run 200m?

• sorry Mr. LSINDHU i found the answer and the concept that you have applied here is little bit wrong.
  the answer is here
  
  Let time taken by A to comple race= t sec for 100m
  speed of A = 100/t
  
  then time taken by B = t+5 sec for 80m
  in case 2 the time taken by B to complete 60m will be (t+5)*60/80 =3(t+5)/4 sec
  
  so time taken by A to complete 100m is also 3(t+5)/4 sec as both of them reached at same time in case2
  
  in both the case A has run 100m. and time taken to cover is also same as his speed does not change.
  so equating the time in both case we get
  t = 3(t+5)/4
  => 4t = 3t + 15
  => 4t-3t = 15
  =>t=15 sec.
  so time taken to cover 100m by A is 15 sec.
  so time taken to cover 200m by A is 15*2 = 30 sec. (ans)
  
  hope, you like my solution friend
  
  
• 10 years agoHelpfull: Yes(1) No(0)
• the question simply means that a beats b by 20m or 5sec.
  so a takes 50sec to run 200m.
• 10 years agoHelpfull: Yes(0) No(0)