A train moving at 40 km/h will take 2 hours 15 minutes more to cover a certain distance than when the speed is doubled. What is the distance?

Speed of the train at first: 40 km/h

Time difference when speed is doubled: 2 hours 15 minutes = 2.25 hours

Time = $$\frac{\text{Distance}}{\text{Speed}}$$​

Let the distance be D km.

So,

​$$\frac{D}{40} - \frac{D}{80} = 2.25 \\ \ \\\frac{2D}{80} - \frac{D}{80} = 2.25 \\ \ \\\frac{D}{80} = 2.25 \\ \ \\$$​​

D = 2.25 × 80 = 180 km

Thus, The distance is 180 km.