If an electric field e= i20+j30 N/C exists in space.. if potential at origin is taken to be zero.find the potential at(2m,2m)??

Remember what the relationship is between electric field and electric potential. If you have a constant electric field, the potential is given by the negative of the electric field times the displacement, plus some constant number C. Since you have a 2D field in this case, you can treat each component individually (so v =-(e_x *x + e_y * y)+C). Then, since you're given the value of the potential at the origin, that tells you what the value of C is that you should use.