Answer:
It seems you're describing a scenario with three small spheres, each carrying a different electric charge:
1. Sphere 1: Charge \(q_1 = 3.50 \, \text{nC}\)
2. Sphere 2: Charge \(q_2 = -7.50 \, \text{nC}\)
3. Sphere 3: Charge \(q_3 = 2.05 \, \text{nC}\)
If you have a specific question or if there's a particular calculation or scenario you'd like to explore with these charges, please provide more details, and I'll be happy to assist you further.