Read the passage below and solve the questions based on it.
A jetfighter moving 3 km above the ground with a speed of 360 km/h tries to cross the border. A radar station notices it at distance of 6 km from the Jet. But it can fire anti-craft missile only when the plane enters in its border. The border is at a distance of km from radar station. (Assume that the fighter moves in a straight line in the same plane with the same speed)
The radar station can fire 10 missiles simultaneously in such a way that the first missile will meet the fighter exactly at the border if the fighter moves with its original speed. The other missiles will reach up to the line of movement of the jet at same time but at a distance of 100 m from each other such that one of them will hit the fighter even if the fighter increases its speed. If jetfighter has to escape the attack, at what increased speed it should move?