In this collision
Coefficient of restitution 0 < e < 1
The loss in kinetic energy appears in other forms, such as heat, sound etc.
Ex- Collision between two billiard balls. All majority of collision belong to this category.
in inelastic collision k. e. is conserved
The sum of the total kinetic energy before collision is not equal to the sum of the total kinetic energy after collision
2nd is also correct
1st and 3rd are correct. I'm not sure about 2nd