Question

if the distance between two equal point charges is doubled and their individual charges are also doubled what wouid happen to the force b/w them?

Answer 1

F between them remains same 

F= k q1 x q2 / r²

now if we doubled 

F= k 2q1 x 2q2  / 4r²
F= 4 k q1 x q2 / 4 r²
F= k q1 x q2 / r²

Answer 2

f will be same

f = k q1q2/r^2

f=k 2(q1q2)/r^2