Electrostatics

Two point charges $+10 \mu \mathrm{C}$ and $4 \mu \mathrm{C}$ are placed 10 cm apart in air. The work required to be done to bring them 2 cm closer is

\(\left(\frac{1}{4 \pi \varepsilon_0}=9 \times 10^9 \text { SI units }\right)\)