A boy is about to cross over a rail way but unfortunately a 300m long train arrived and passed by him. how long does he need to wait to cross?

Answer: To determine how long the boy needs to wait to cross the railway, we need to consider the time it takes for the entire train to pass by him.

The length of the train is given as 300 meters.

We also need to know the speed of the train to calculate the time it takes to pass the boy. Let’s assume the speed of the train is v meters per second.

The time it takes for the train to pass the boy can be calculated using the formula:

Time = Distance / Speed

In this case, the distance the train needs to cover to pass the boy is 300 meters.

Therefore, the time needed for the train to pass the boy is:

Time = 300 meters / v meters per second

Without knowing the speed of the train, we cannot calculate the exact time the boy needs to wait to cross the railway. If the speed of the train is provided, the time can be calculated.