If each lap has a diameter of 30 meters, let's calculate the total distance of 10 laps:
[tex]\begin{gathered} 1\text{ lap:} \\ C=\pi\cdot d=3.1416\cdot30=94.25\text{ m} \\ \\ 10\text{ laps:} \\ 10\cdot C=10\cdot94.25=942.5\text{ m} \end{gathered}[/tex]Now, calculating how many meters are needed to reach 1 km, we have:
[tex]1000-942.5=57.5\text{ m}[/tex]