Electrical Force Homework: Double Charge, Double Distance, 2x Force

[VLC]

Homework Statement

Two charged particles repel each other with a force of F. if the charge of one of the particles is doubled and the distance between them is also doubled, then the force will be?

Homework Equations

The Attempt at a Solution

Answer = 2F

 

[ideasrule]

F=kq1q2/r^2

I replace q1 with 2q1 and r with 2r. F=?