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A train travels 360 km at a uniform speed. If the speed had been 5 km/h more, it wo
have taken 1 hour less for the same journey. Find the speed of the train.
360
Answers
Answer:
You can solve this by making to equation by using time formula.
Original Speed= 40 km/h
Step-by-step explanation:
Let the original speed of train = x km/h
According to first situation :-
time=distance/speed
= 360/x .........(i)
According to second situation where
speed is 5 km/h more or speed = x + 5 km/h :-
time= distance/speed
= 360/x+5 ...........(ii)
From equation i & ii
A/q.
360/x - 360/x +5 = 1
(360x + 1800 - 360x)/(x^2 + 5x) =1
1800 = x^2 +5x ( by cross multiply)
or x^2 +5x-1800=0 (it's a quadratic equation)
x^2 +45x-40x-1800=0 (spliting middle value)
x(x+45) -40(x+45)
(x-40) (x+45)
where 'x' can be 40 or -45
as speed can't be negative so
speed of train = x= 40 km/h
