The force (F) of attraction or repulsion between two point charges (Q1 and Q2) is given by the following rule:
F = (k * q1 * q2) / (r^2) where:
q1 and q2 are the charges
k is coulomb's constant = 9 x 10^9 N. m2/ C2
r is the distance between the two charges.
Applying the givens in the mentioned equation, we find that:
F = (9 x 10^9 x 0.07 x 10^6 x 2) / (0.0108)^2 = 1.08 x 10^19 n