Charges $2\mathrm{q}, -\mathrm{q}$ and $-\mathrm{q}$ lie at the vertices of an equilateral triangle. The ratio of magnitude of $\mathrm{V}$ and  $\mathrm{E}$ at the centroid of the triangle will be ……..

Potential at P will be superposition  of potentials of all three charges

V_P $=\frac{K(-q)}{{\displaystyle \frac{a}{\sqrt{3}}}}+\frac{K(-q)}{{\displaystyle \frac{a}{\sqrt{3}}}}+\frac{K\left(2q\right)}{{\displaystyle \frac{a}{\sqrt{3}}}}=0$

Electric field at P will superposition of electric field of all three charges.

It will not be zero.