please answer the question

The space between two concentric conducting spherical shells of radii b = 1.90 cm and a = 1.30 cm is filled with a substance of dielectric constant K = 23.9. A potential difference V = 95.0 V is applied across the inner and outer shells. Determine (a) the capacitance of the device, (b) the free charge q on the inner shell, and (c) the charge q induced along the surface of the inner shell. (a) Number Units (b) Number i Units v (c) Number Units