A train covers a distance of 300 km at a certain speed. If the speed was decreased by 10km/hr , the journey would have taken 1 hour longer . What is the average speed of the train ?
Answers
Answered by
34
1) distance covered = 300 km
let the speed of the train = x km/hr
time (t1) = distance/ speed
t1 = 300/ x------(1)
2) distance = 300 km
speed = (x- 10) km
t2 = 300 / (x-10)----(2)
given t2-t1 = 1 hr
300/(x-10) - 300/x = 1
[300x - 300(x-10)]/ (x-10)x =1
300x -300x +3000 = (x-10)x
3000 = (x-10) x
let x= 60
3000 = (60-10) *60 [true]
therefore
speed of the train = x = 60km/hr
let the speed of the train = x km/hr
time (t1) = distance/ speed
t1 = 300/ x------(1)
2) distance = 300 km
speed = (x- 10) km
t2 = 300 / (x-10)----(2)
given t2-t1 = 1 hr
300/(x-10) - 300/x = 1
[300x - 300(x-10)]/ (x-10)x =1
300x -300x +3000 = (x-10)x
3000 = (x-10) x
let x= 60
3000 = (60-10) *60 [true]
therefore
speed of the train = x = 60km/hr
Answered by
7
Answer:
60km/h
Step-by-step explanation:
Let speed of train be x
Speed=distance/time
Time=distance/speed
ATQ,
300/(x-10) - 300/x = 1
[300x - 300(x-10)]/ (x-10)x =1
300x -300x +3000 = (x-10)x
3000 = (x-10) x
3000 = x2-10x
x2-10x-3000=0
Solve for answer
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