What is difference between collinear & coplanar vectors ? 

If  vector AO + OB = vector BO + OC , then A , B , C are coplanar or collinear ?

 they are maybe collinear but they are guaranteed coplanar unless you are not studying them in 3D geometry 

They are collinear if AO =AC else they are coplanar

Since vector AO+OB=BA

and vector BO+OC=CB

both the vectors have a common point B therefore they are collinear

is this question based on maharastra textbooks