If the time in Greenwich is 9:00 PM on Monday, then what will be the corresponding time in the country F.
Longitude of the country F with respect to Greenwich => (50−20) = 30∘E
Time increment from GMT to the country F = 30×4 = 120 min = 2 hr.
Therefore, corresponding time in the country F with respect to Greenwich is 11:00 PM on Monday.