Answer:
The 50º West meridian is an imaginary line that crosses from the north pole to the south pole, passing through the center of Greenland and Brazil. Both nations, in the part of the territory that this imaginary line crosses, have a time zone of -3 UTC.
In turn, the 45º East meridian also goes from the north pole to the south pole, but this passes through the eastern part of the European continent, the Caucasus, the Arabian Peninsula and the Somali Peninsula, as well as through the center of Madagascar, regions that have a time zone of +3 UTC.
Therefore, if it were 12 noon at the 50º West meridian, it would be 6 PM at the 45º East meridian.