# Charges set up in a tetrahedron

**Electricity and Magnetism**Level 4

4 positive charges of magnitude \(Q\) are kept on the corners of a regular tetrahedron, and a charge of magnitude \(q_o\) is kept inside the tetrahedron such that system is in equilibrium.
If the ratio \(\frac{Q^2}{q_o ^2}\) can be expressed as \(\frac{a}{b}\) then find the value of \(a+b\).