The great circle distance from LAT 08°50.0'N, LONG 80°21.0'W to LAT 22°36.0'N, LONG 128°16.0'E is 7801 miles and the initial course is 318°45' T. The latitude of the vertex is 49°20.6'N. What is the longitude of the vertex?

Correct Answer: Option C — 162°41'W

The vertex of a great circle track is the point of highest latitude. Using the formula cos(Lon_v - Lon_1) = tan(Lat_1) / tan(Lat_v), where Lat_1 is 08°50.0'N and Lat_v is 49°20.6'N, the difference in longitude is calculated as 73°40.1'. Applying this to the departure longitude yields 162°41'W.