1. The problem statement, all variables and given/known data 2. Relevant equations 3. The attempt at a solution my ans is f Y = 260hz. but the ans is f Y= 252hz . am i wrong? why? Since X is 256Hz., when sounded with Y 4 beats are produced, so Y is either sounding at 260 or 252Hz (+-4Hz). When Z is sounded with X, 8 beats are heard, so Z is either 264 or 248Hz.(+-8Hz). my fZ is (264Hz.) now the f Y can be 260 or 252Hz (+-4Hz). which one to choose?