Work needed to move a point charge

[TrpnBils]

Homework Statement

A +30μC charge is placed 32cm from an identical charge. How much work would be required to move a +0.50μC test charge from a point midway between them to a point 10cm closer to one of the charges.

Homework Equations

W = qV
V = kQ/r

The Attempt at a Solution

Tried solving with +30μC as the Q value, r as 0.32m, and q as the test charge but I'm getting this wrong. The answer is 1.08 Joules. I know that the work done = ΔPE between the two locations, but I'm not sure how to calculate this given that BOTH charges on the ends are pushing it away...

 

[SammyS]

Homework Statement

A +30μC charge is placed 32cm from an identical charge. How much work would be required to move a +0.50μC test charge from a point midway between them to a point 10cm closer to one of the charges.

Homework Equations

W = qV
V = kQ/r

The Attempt at a Solution

Tried solving with +30μC as the Q value, r as 0.32m, and q as the test charge but I'm getting this wrong. The answer is 1.08 Joules. I know that the work done = ΔPE between the two locations, but I'm not sure how to calculate this given that BOTH charges on the ends are pushing it away...

What is the electric potential, due to the two +30μC charges, at a point midway between them and at a point 10cm closer to one of the charges.