What force would be this replaced charge experience?

[aeromat]

Homework Statement

A charge q1 = +4.0nC experiences a force of 3*10^-5N to the east when placed in an electric field. If the charged is replaced by another, q2 = -12nC, what will be the magnitude and direction of the force on the charge at that position?

Homework Equations

Coulomb's Law
Electrostatic Forces
Electric Field Intensity

The Attempt at a Solution

I am getting confused by the wording of this question.

I know that E = Fe/qT = k(qS)/r^2
How would I go about with solving this problem? Does it have to do with the relationship between the variables, because I noticed that the new charge is 3 times the magnitude of the replaced one.

 

[gneill]

I know that E = Fe/qT = k(qS)/r^2

What are T and S in the above?