Two point charges ql = +2.40 nC and q2 = -6.50 nC are 0.100 m apart. Point

Question:

Two point charges ql = +2.40 nC and q2 = -6.50 nC are 0.100 m apart. Point A is midway between them; point B is 0.050 m from ql and 0.060 m from q2 (Fig). Take the electric potential to be zero at infinity. Find
(a) The potential at point A;
(b) The potential at point B;
(c) The work done by the electric field on a charge of 2.50 nC that travels from point B to point A.