Answer:
10.58km
Explanations:
The formula needed to calculate the amount of wire used is expressed as:

W is the weight of wire used to wind a magnet
wg is the weight of wire per km
Given the following parameters:

Substitute the given parameters into the formula to have:
![\begin{gathered} \text{Length of wire used=}\frac{471\cancel{g}}{44.5\cancel{g}km^(-1)} \\ \text{Length of wire used}=(471)/(44.5)km \\ \text{Length of wire used=}10.58\operatorname{km} \end{gathered}]()
Hence the length of wire used is 10.58km