Due to some technical problems, an aeroplane started late by one hour from it starting point. The pilot decided to increase the speed of the aeroplane by 100 km/hr. from its usual speed, to cover a journey of 1200 km in time. Find the usual speed of the aeroplane? What value (Quality) of the pilot is represented in the question?
Value Based Question
Answers
Answered by
8
Let the original speed be 'x'
Total distance=1200
Time=D/S
Original time taken (OT) = 1200/x
New time (NT) = 1200/(x+100)
According to the question
OT - NT = 1
1200/x - 1200/(x+100) = 1
[1200(x+100)-1200x]/x(x+100)=1
[1200x +120000-1200x]/(x²+100x)=1
120000 = x²+100x
x²+100x-120000 = 0
x²+400x-300x-120000 = 0
x(x+400) - 300(x+400) = 0
(x+400) (x-300) = 0
x = -400
x = 300
Speed cannot be negative.
Therefore, x= 300
The speed is 300 km/hr Answer.
Total distance=1200
Time=D/S
Original time taken (OT) = 1200/x
New time (NT) = 1200/(x+100)
According to the question
OT - NT = 1
1200/x - 1200/(x+100) = 1
[1200(x+100)-1200x]/x(x+100)=1
[1200x +120000-1200x]/(x²+100x)=1
120000 = x²+100x
x²+100x-120000 = 0
x²+400x-300x-120000 = 0
x(x+400) - 300(x+400) = 0
(x+400) (x-300) = 0
x = -400
x = 300
Speed cannot be negative.
Therefore, x= 300
The speed is 300 km/hr Answer.
Similar questions