A cylindrical aluminum pipe of length 1.57 m has an inner radius of 2.20 x 10-3 m and an outer radius of 2.80 x 10-3 m. The interior of the pipe is completely filled with copper. What is the resistance of this unit? (Hint: Imagine that the pipe is connected between the terminals of a battery and decide whether the aluminum and copper parts of the pipe are in series or in parallel.)