In the example, ZD +5 is centered on which longitude?

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Multiple Choice

In the example, ZD +5 is centered on which longitude?

Zone designators on charts correspond to standard time zones that are 15 degrees of longitude wide, with each zone centered on a specific meridian. A zone centered on 75°W has boundaries at 75°W ± 7.5°, giving 82.5°W and 67.5°W. Since ZD +5 means the zone five hours behind UTC (the zone whose standard meridian yields that offset), its center is 75°W. Therefore, the longitude it is centered on is 75°W. The numbers 67.5°W and 82.5°W are the zone’s boundaries, not its center, and 90°W belongs to a different time zone.

Zone designators on charts correspond to standard time zones that are 15 degrees of longitude wide, with each zone centered on a specific meridian. A zone centered on 75°W has boundaries at 75°W ± 7.5°, giving 82.5°W and 67.5°W. Since ZD +5 means the zone five hours behind UTC (the zone whose standard meridian yields that offset), its center is 75°W. Therefore, the longitude it is centered on is 75°W. The numbers 67.5°W and 82.5°W are the zone’s boundaries, not its center, and 90°W belongs to a different time zone.

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