What is the relation among three classes

Hello

Automobile :

Automobile is way of transport either any kind of stuffs or human being .

It is just like median between transportation

Bike :

Bike is way to achieve transportation

It is asset via we can do transportation as option for Automobile

Engine :

Engine is part of any vehical that act as neccessary asset for vehical to move

Without engine we can not achieve transportation

So in terms of relationship everything is depends on each other

Transportation must have > Bike [Or other vehical] can work base on > Engine

Thats what i can explain

Thanks