To travel 708 km, an Express train takes 6 hours more than Rajdhani train. If however, the speed of the Express train is doubled, it takes 3 hours less than Rajdhani train. What is the speed of Rajdhani train?

To travel 708 km, an Express train takes 6 hours more than Rajdhani train. If however, the speed of the Express train is doubled, it takes 3 hours less than Rajdhani train. What is the speed of Rajdhani train? Correct Answer 59 km/hr

According to the given information,

Let’s assume speed of Rajdhani train to be ‘x’ km/hr

And, speed of Express train to be ‘y’ km/hr

We know that,

Time = Distance/Speed

⇒ Time taken by Rajdhani train = 708/x

⇒ Time taken by Express Train = 708/y

⇒ 708/y - 708/x = 6                    -------Equation (1)

If Speed of Express train is doubled,

⇒ Time taken by express train = 708/2y

⇒ 708/x - 708/2y = 3                   --------Equation (2)

Adding Equation (1) and 2 × Equation (2), we get,

⇒ 1416/x - 708/x = 12

⇒ 708/x = 12

∴ x = 708/12 = 59 km/hr