¿Qué distancia (d) se tiene entre la posición A (l = 36º 20,0´N L = 006º 19,0´W) y la posición B (l = 36º 20,0´N L = 006º 10,0´W)?What is the distance (d) between position A (l = 36º 20.0'N L = 006º 19.0'W) and position B (l = 36º 20.0'N L = 006º 10.0'W)?

Correct answer: b) d = 7.3 miles.

Why it is correct

Same latitude: distance is the departure. Difference of longitude 9′ × cos 36º20′ = 7.25, about 7.3 miles.

Why the others are not

• a) It forgets that a minute of longitude is not a mile.
• c) This does not follow from the data.
• d) This does not follow from the data.

How to work it out in the exam

1. Departure = difference of longitude × cosine of latitude.
2. On the chart, always measure on the latitude scale.

Where this question comes from

• Ministerio de Transportes (Madrid) · 2021 · Convocatoria de julio · PER Test 2 · question 45 Official paper · Official answer key
• Ministerio de Transportes (Madrid) · 2021 · Convocatoria de julio · PER Test 4 · question 42 Official paper · Official answer key

Try it: Navigation calculations

Pending instructor review. Machine translation, not reviewed.