A circular running track has six lanes, each $1$ $\text{m}$ wide. How far ahead (in metres) should the runner in the outermost lane start from, so as to cover the same distance in one lap as the runner in the innermost lane?
$10 \pi$
The problem asks for the starting distance difference required for a runner in the outermost lane of a circular track to cover the same distance as a runner in the innermost lane.
There are 6 lanes, each 1 meter wide. The difference in the radius of the running path between the outermost lane and the innermost lane is determined by the number of lanes and their width.
Let $r_{in}$ be the radius of the path for the runner in the innermost lane. The radius for the runner in the outermost lane, $r_{out}$, is $r_{out} = r_{in} + 5 \text{ m}$.
The distance covered in one lap is the circumference of the circular path. The formula for the circumference ($C$) of a circle is $C = 2 \pi r$.
The runner in the outermost lane covers $10 \pi$ meters more distance than the runner in the innermost lane for each lap completed around the same starting point. To cover the *same* distance, the runner in the outermost lane must start ahead. The distance they need to start ahead is exactly the difference in the distance they cover in a lap.
Therefore, the runner in the outermost lane should start $10 \pi$ meters ahead.