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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
Read Solution (Total 13)
-
- x=600/y
x-200=600/y+1/2
y=1 hour - 14 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. - 14 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 - 14 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 - 14 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 - 13 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. - 14 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 - 13 years agoHelpfull: Yes(3) No(0)
- 3hr
- 14 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 - 9 years agoHelpfull: Yes(2) No(0)
- 1hr
- 14 years agoHelpfull: Yes(1) No(4)
- any where it isn't mentioned about 1hr my frnd dipin
- 14 years agoHelpfull: Yes(1) No(3)
- 600/x-600/(x+1/2)=200
solve it we will get x=1 which is required time - 13 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) - 14 years agoHelpfull: Yes(0) No(1)
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