The solution to your problem is as follows:
Since,
F = Σ kQq / d²
Then,
F = 8.99e9N·m²/C² * (5.20nC/(0.400m)² - 3.85nC/(0.195m)²) * -0.615nC
F = 3.8e-7 N
Therefore, the magnitude of the total force exerted by these two charges on a negative point charge is 3.8e-7 N.
I hope my answer has come to your help. Thank you for posting your question here in Brainly.
