GRE GMAT TESTs AND SOLUTIONs

There are six different models that are to appear in a fashion show. Two are from Europe, two are from South America, and two are from North America. If all the models from the same continent are to stand next to each other, how many ways can the fashion show organizer arrange the models? A) 48 B) 64 C) 24 D) 8 E) 72

A group of seven students is to be seated in a row of seven desks. In how many different ways can the group be seated if two of the preselected students must sit in an end seat (i.e., two students have been preselected to sit in either the first or the seventh seat)? A) 49 B) 100 C) 120 D) 240 E) 720