A train travels a distance of 300 km at a constant speed. If the speed of the train 'is increased by 5 km an hour.

Question

Represent the following situations in the form of the quadratic equation.

A train travels a distance of 300 km at a constant speed. If the speed of the train 'is increased by 5 km an hour. The journey would have taken two hours less.

Answer 1

Let ‘x’ be the speed of the train in km per hour.

∴ Time taken to cover 300 km = 300/x

[∵ Time = Distance/Speed .]

∴ Time taken when speed is increased by 5 = 300/(x + 5)

∵ The journey would have taken two hours less when speed is decreased.

Difference in time = 300/x = 300/(x + 5) = 2