Cory, Srey, Molly, and Mao each visited a different city: Santa Clara, Seattle, Des Moines, and Pittsburgh. Cory and Molly visited cities with two words in their names. Mao and Cory visited cities whose names start with an S. Where did Molly visit?

Since Cory and Molly visited cities with two words in their names, then the choices for Molly's visited city will be narrowed down to just Santa Clara or Des Moines. Now, since Cory visited a city whose name starts with an S, then we are sure that the city visited by Cory was Santa Clara. Now, there's only one city left to be Molly's visited city, and that is Des Moines. Therefore, Molly visited Des Moines.