35. In a flight of 600 km, an aircraft was slowed down due to bad weather. Its average speed for the trip was reduced by 200 km/hr and the time of flight increased by 30 minutes. The duration of the flight is:
(a) 1 hour (b) 2 hours (c) 3 hours (d) 4 hours

• x=600/y
  x-200=600/y+1/2
  y=1 hour
• 13 years agoHelpfull: Yes(16) No(3)
• Normal speed is 600 km/hr and normal time taken is 1 hr.
  
  If speed is reduced to 400 km/hr, time taken is 1.5 hrs means 30 min more than normal time.
  
  so normal duration of flight is 1 hr.
• 13 years agoHelpfull: Yes(12) No(12)
• x=600/y..........(1)
  x=average speed
  y=time
  now in 2nd case,
  x-200=600/(y+1/2)......(2)
  from eqn (1) and (2)
  y=1 hour
• 13 years agoHelpfull: Yes(12) No(1)
• Take normal speed=s,distance=d=600km,time=t=600/s.
  If speed is reduced by 200km/h and the time of flight increased by 30 minutes(1/2 hours),
  i.e,speed=s-200 km, distance=600km and time=600/s + 1/2 = 600/(s-200)-----(1),
  solving (1), s=600 km/h,
  therefore normal speed=600km/h and duration of the flight=600/600=1hr
• 13 years agoHelpfull: Yes(6) No(2)
• Lets say the duration of flight is X hrs
  thus speed is 600/x
  now duartion is x+0.5 hrs
  thus speed is 600/(x+0.5)
  600/x - 600/(x+0.5) = 200
  this forms a quadratic eqn.
  x comes out to be 1 and -3/2
  
  Ans
  (a) 1 hour
• 12 years agoHelpfull: Yes(4) No(0)
• x=600/y
  x-200=600/(y+1/2)
  now put y=1 then x=600
  if you put these two value in 2nd equation then it will satisfy.so answer willl be 1 hr.
• 13 years agoHelpfull: Yes(3) No(0)
• let avg speed=xkm/hr.after reduce avg speed will be(x-200)km/hr
  total distance=600km
  600/(x-200) - 600/x=1/2
  .
  .
  x^2-200x-240000 by factorizing we get x=600km/hr..
  so ans=1hr
• 12 years agoHelpfull: Yes(3) No(0)
• 3hr
• 13 years agoHelpfull: Yes(2) No(39)
• avg. speed = 600 then duration (time) = X
  
  avg. speed = 400 duration = X + 30
  
  NOW DISTANCE IS EQUAL
  
  D=S * T
  
  600 * X = 400 * ( X + 30 )
  
  X = 60 minute
  
  ans = 1 hour
• 8 years agoHelpfull: Yes(2) No(0)
• 1hr
• 13 years agoHelpfull: Yes(1) No(4)
• any where it isn't mentioned about 1hr my frnd dipin
• 13 years agoHelpfull: Yes(1) No(3)
• 600/x-600/(x+1/2)=200
  solve it we will get x=1 which is required time
• 12 years agoHelpfull: Yes(1) No(1)
• let duration of the flight is x.
  now from the prob. 600/x[normal speed]-600/(x+1/2)[after reduction of speed]=200
  [30min=1/2hr=time increased]
  ans:x=1(x can not negative)
• 13 years agoHelpfull: Yes(0) No(1)