A train covers 360 km at a uniform speed. If the speed had been 5 km/h more, it would have taken 1 hour less. Let the speed be x km/h. From 360/x - 360/x+5 = 1, form a quadratic and solve by factorisation. What is the original speed (in km/h)?

Question

Accepted Answer

40 km/h. 360/x - 360/x+5 = 1 gives 360*5 = x(x+5), i.e. x^2 + 5x - 1800 = 0 = (x + 45)(x - 40). x = 40 (reject -45). Speed = 40 km/h.

A train covers 360 km at a uniform speed. If the speed had been 5 km/h more, it would have taken 1 hour less.
Let the speed be $x$ km/h. From $\frac{360}{x} - \frac{360}{x + 5} = 1$ , form a quadratic and solve by factorisation.
What is the original speed (in km/h)?

Step-by-Step Solution

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More Class 10 Solving by Factorisation practice

A train covers 360 km at a uniform speed. If the speed had been 5 km/h more, it would have taken 1 hour less.Let the speed be x km/h. From x360​−x+5360​=1, form a quadratic and solve by factorisation.What is the original speed (in km/h)?

Step-by-Step Solution

Master this chapter in 30 minutes a day.

More Class 10 Solving by Factorisation practice

A train covers 360 km at a uniform speed. If the speed had been 5 km/h more, it would have taken 1 hour less.
Let the speed be $x$ km/h. From $\frac{360}{x} - \frac{360}{x + 5} = 1$ , form a quadratic and solve by factorisation.
What is the original speed (in km/h)?