1. The g factor = (mu / mu_N) * (h_bar / I). For the ground state of 111Cd we have mu = -0.5940 nm and I = 1/2 * h_bar. Filling this in the formula above gives a g factor of -1.188 (dimensionless). For the 245 keV level, mu = -0.766 nm and I = 5/2 * h_bar. This gives a g factor of -0.3064.
2. mu_e = -g * mu_B * 1/2. If mu_e = mu_B, then g = -2.
3. (mu / mu_N) = g * (I / h_bar). Neutron is a spin 1/2 particle so I = 1/2 * h_bar and g = -3.826. This gives a mu = -1.913 nm (nuclear magneton).