Inductive time constant = L / R (*where L=inductance, R=resistance)

Part B:

If a resistor and indcutor are connected in a series to a battery of emf e at time t=0, the current in the circuit varies intime according to the following formula:

I= e/R (1-e^(-t/t) (*where e=emf, R=resistance, t=time,t=inductive time constant)

plugging in the corresponding values will give you I.

Part C:

The final steady state current, is defined by Ohm's Law, as: