Hover or tap underlined Spanish terms to see their translation and exam tip.
A las 03:30 horas UTC del día 15, ¿cúal será la hora legal en un lugar de longitud = 100° 10'' W?At 03:30 UTC on the 15th, what will be the zone time (hora legal) at a place of longitude 100° 10' W?
Show the answer
Correct answer: a) 20:30 on the 14th.
Why it is correct
Dividing longitude by 15° gives 100° 10′ / 15° = 6 with a remainder of 10° 10′. Since the remainder exceeds 7° 30′, we round up to zone +7 W (UTC − 7 h). Subtracting 7 hours from 03:30 UTC on the 15th gives 20:30 on the 14th.
Why the others are not
- b) 21:30 on the 14th would correspond to zone +6 W (which ends at 097° 30′ W).
- c) 09:30 on the 15th adds 6 hours (as if in East longitude zone −6).
- d) 10:30 on the 15th adds 7 hours (which would apply to 100° 10′ E, not W).
How to work it out in the exam
- 100° 10′ W → zone +7 W (UTC − 7 h): 03:30 UTC on the 15th − 7 h = 20:30 on the 14th.
Where this question comes from
- Ministerio de Transportes (Madrid) · 2020 · Convocatoria de diciembre · CY Test 1 · question 3 Official paper · Official answer key
Pending instructor review. Machine translation, not reviewed.