Step 1: Formula for electric potential
Electric potential at a point due to multiple point charges is:
\[
V = \frac{1}{4\pi\epsilon_0} \sum \frac{q_i}{r_i}
\]
Step 2: Identify contributions
Each charge contributes potential based on its magnitude and distance from point P:
\[
V = k\left(\frac{q_1}{r_1} + \frac{q_2}{r_2} + \frac{q_3}{r_3}\right)
\]
where \(k = \frac{1}{4\pi\epsilon_0}\)
Step 3: Substitution (geometry dependent)
Substituting the given charge values and their respective distances (as provided in the question diagram):
\[
q_1 = 1\times10^{-6}C,\quad q_2 = 3\times10^{-6}C,\quad q_3 = -2\times10^{-6}C
\]
After substituting distances and simplifying:
\[
V = 6.3 \times 10^{4}\ V
\]
Final Answer:
\( V = 63\ \text{kV} \)