a) 8.45 ns.
b) 7.37 mA.
a) Inductance is 0.29 mH.
b) Resistance of wire is 1.0 ohm, so the inductive time constant is 0.29 ms.
a) i1 = i2 = 3.33 A.
b) Effective resistance of three resistors is 22 ohm. Thus i1 = 4.55 A; i1 = 2.73 A.
c) i2 = 1.82 A, immediately on the switch opening, since it is now in series with the inductive branch, which had the current 4.55 A-2.73 A through it from part b).
d) All currents diminish to zero after power source is removed.