1. A particle \(P\) of mass \(3 m\) and a particle \(Q\) of mass \(2 m\) are moving along the same straight line on a smooth horizontal plane. The particles are moving in opposite directions towards each other and collide directly.

Immediately before the collision the speed of \(P\) is \(u\) and the speed of \(Q\) is \(2 u\).
Immediately after the collision \(P\) and \(Q\) are moving in opposite directions.
The coefficient of restitution between \(P\) and \(Q\) is \(e\).

1. Find the range of possible values of \(e\), justifying your answer. Given that \(Q\) loses 75\% of its kinetic energy as a result of the collision,
2. find the value of \(e\).