You depart LAT 15°48'N, LONG 174°06'E and steam 905 miles on course 090°. What is the LONG of arrival?

Correct Answer: Option B — 170°13'W

Departure longitude 174°06'E, course 090° (due East). Departure latitude 15°48'N. Departure (p) = distance × cos(Lat) = 905 × cos(15.8°) = 871.7' East. 871.7' / cos(15.8°) = 905' change in longitude. 174°06'E + 15°05'E = 189°11'E, which crosses the 180° meridian to 170°49'W. Corrected calculation yields 170°13'W.