Solve the given question:
Question: Two ice skaters, with masses of 30kg and 85kg, are at the center of a 40m -diameter circular rink. The skaters push off against each other and glide to opposite edges of the rink.
Question I: If the heavier skater reaches the edge in 30s, how long does the lighter skater take to reach the edge?
Please use as much detail as possible in your answer. Thank you.