A train crosses a 400 m-long platform in 50 seconds. It crosses another 600 m-long platform in 60 seconds. What are the length and the speed of the train?

600 m; 72 km/h

Let length of train is = a meter

Speed is same in both the cases .

Distance = Speed × Time

According to question ,

$\frac{400 + a}{50}$ = $\frac{600 + a }{60}$

2400 + 6a = 3000 + 5a

a = 600 m

Speed of train = $\frac{400 + 600}{50}$

= $\frac{1000}{50}$ = 20 m/sec

20 m/sec = 20 × $\frac{18}{5}$ km/h = 72 km/h

So , Length of train is 600 m and Speed of train is 72 km/h