Let S be the slower ship and F be the faster ship. It is given that when S travelled 8km, the positions of ships with the port is forming a right triangle. Since one of the angles is 60 (since one vertex is still part of the equilateral triangle), the other two vertexes will have angles of 30 and 90 . The distance between O and S=24−8=16 In triangle OFS,cos60°=
OF
OS
Thus, OF=8. Thus in the time, S covered 8km,F will cover 24−8=16km. Thus, the ratio of their speeds is 2:1, Thus, when F covers 24km, S will cover 12km. The correct option is B