This is actually homework for calc. III, but...eh... The nine Ring Wraiths want to fly from Barad-Dur to Rivendell. Rivendell is directly north of Barad-Dur. The Dark Tower reports that the wind is coming from the west at 68 miles per hour. In order to travel in a straight line, the Ring Wraiths decide to head northwest. At what speed should they fly (omit units)? Does anyone know how to attempt this problem when they don't give either the distance from Barad-Dur to Rivendell or the angle they are heading northwest?