Question

In a flight for 6000km, an aircraft was slowed down due to bad weather. Its average speed for the trip was reduced by 400km/hr and consequently time of flight increased by 30 minutes. Find the original duration of flight

Answer 1

Step-by-step explanation:

this is the answer of this question

Answer 2

Answer:

2.5 hrs or 150 mins

Step-by-step explanation:

in case 1,

given, distance of flight = 6000km=d

let, speed=s

     time=t

since, speed=distance/time

distance=speed x time  or  d=s x t

6000=st     ........................ ( 1 )

in case 2,

speed is reduced by 400kmph so time increases by 30 mins or 1/2 hr

since distance remains the same

6000=(s-400)(t+1/2)    .............................. ( 2 )

eq ( 1 ) =eq ( 2 )

st=st -400t + s/2 - 200

st-st= s/2 -400t -200

0= s/2 -400t -200

s/2=400t + 200

s=800t + 400   ................................ ( 3 )

sub ( 3 ) in ( 1 )

6000=t(800t+400)

6000= 800t²+400t

800t²+400t-6000=0

2t²+t-15=0

2t²+6t-5t-15=0

2t(t+3)-5(t+3)=0

(2t-5)(t+3)=0

t=5/2 hrs or t=-3 hrs

since time cant be negative

original duration of flight=5/2hrs or 2.5hrs or 150 mins