To travel 612 km, Train A takes 9 hours more than Train B. If the speed of the Train A is doubled, it takes 3 hours less than Train B. The speed (in km/h) of Train B is:
Given Distance = 612 km
Let the speed of B is x km/hr
So, Time taken by B to cover 612 km = $$\frac{612}{x}hr$$
Time taken by A to cover 612 km = $$\left(\frac{612}{x}+9\right)hr$$ (given)
Speed of Train A = $$\left(\frac{612}{\frac{612}{x}+9}\ \right)\frac{km}{hr}$$
According to Question,
$$612=2\times\ \left(\frac{612}{\frac{612}{x}+9}\right)\times\ \left(\frac{612}{x}-3\right)$$
$$\frac{612}{x}+9=2\times\ \left(\frac{612}{x}-3\right)$$Create a FREE account and get: