A 200 m long train passes a motorcycler, running in the same direction at 12 km/hr, in 15 second and a jeep travelling in the same direction in 20 s. At what speed is the car travelling (length of both the motorcycler and jeep is negligible)?

Let the speed of the train be 'S' kmph

From the given data,

Distance = Length of train = D = 200 mts = 200 x 18/5 kms

Time = 10 sec

given speed of the motorcycler = 12 kmph

Relative speed as they are moving in the same direction = (S - 12) kmph

$(S-\; 12) = \frac{200 x \frac{18}{5}}{15}S - 12 = 48S = 60 \mathrm{kmph}$

Hence, the speed of the train = S = 60 kmph

Now,

Let the speed of the jeep be 'x' kmph

$60 - x = \frac{200 x \frac{18}{5}}{20}60 - x = 36x = 60 - 36x = 24 \mathrm{kmph}$

Therefore, the speed of the jeep = x = 24 kmph.