5 : 8....added = 13
5/13(169) = 845/13 = 65 men
8/13(169) = 1352/13 = 104 women <===
In 8 weeks the reef grows 13 m, or 104 m.
Converting 104 m into mm:
104 m 1000 mm
--------- * ------------- = 104,000 mm
1 1 m
Radius = 24.49
Hope this helps! (If not sorry!)