A long, hollow, cylindrical conductor $($inner radius $3\mathrm{.}3$ mm$,$ outer radius $6\mathrm{.}7$ mm$)$ carries a current of $43$ A distributed uniformly across its cross section. A long thin wire that is coaxial with the cylinder carries a current of $55$ A in the opposite direction. What is the magnitude of the magnetic field $($a$)1\mathrm{.}1$ mm$,($b$)3\mathrm{.}5$ mm$,$ and $($c$)7\mathrm{.}7$ mm from the central axis of the wire and cylinder?