Furthermore, they detect a series of channels, each of which is a perfect circle formed by the intersection of a plane with the planet’s surface.
Suspecting that the channels were dug by intelligent beings, the five start out looking for artifacts.
Hannah follows one channel and finds its length to be 30 kms in circumference.
Jack follows a longer channel which does not cross Hannah’s.
Dana’s channel is 50 kms and crosses Jack’s.
Ron’s channel is 60 kms and also crosses Jack’s.
Finally, Sarah follows a channel which is the maximum possible circumference.
Determine the length of Sarah’s channel.
