A great circle crosses the equator at 162°E. It will also cross the equator at what other longitude?

Correct Answer: Option D — 18°W

Equatorial crossings of a great circle are separated by exactly 180 degrees of longitude. Subtracting 180° from 162°E yields 18°W, representing the antipodal point where the great circle track intersects the equator in the opposite hemisphere, as detailed in Bowditch.