A train 'B' speeding with 100 kmph crosses another train C, running in the same direction, in 2 mins. If the length of the train B and C be 150m and 250m respectively, what is the speed of the train C (in kmph) ?

Given, speed of train B = 100 kmph

Let speed of train C = x kmph

length of train B = 150 m = 0.15 km 

length of train C = 250 m = 0.25 km

time taken = 2 mins = $$\frac{2}{60}$$ = $$\frac{1}{30}$$ 

time taken = $$\frac{length trainA +length train B}{difference in speed}$$ =$$\frac{0.4}{100 - x}$$

$$\frac{1}{30} = \frac{0.4}{100 - x}$$

$$100 - x = 0.4 \times 30$$

$$100 - 12= x$$

x( speed of the train C) = 88 kmph