What time is it 13 half-hours after 6:30 p.m.?

Which British liner, torpedoed by the German submarine U-20 on May 7, 1915, sank in about 18 minutes? In 1281, a "divine wind" saved which nation from a Mongol invasion? In 1290, King Edward I expelled all Jews from which nation? In 1297, Francois Grimaldi, disguised as a monk, seized the fortress of which future principality? Which word for a long journey, especially on foot, shares its Latin root with the name of the peregrine falcon? What name is given to a group of 13 loaves or buns? Thirteen items, as a bread seller traditionally counts them, make up what? What name is traditionally given to a group of 13 witches?