A teacher is 15 years older than her student, who is
, and thus the teacher is . In 15 years, the
ratio of their ages will be 3:2, because the teacher will be
 and the student will be , and the fraction
 equals to the fraction  .

How'd I get that?  By using the same words as I did above,
only using  for the student's age instead of .

A teacher is 15 years older than her student, who is ,
and thus the teacher is . In 15 years, the ratio of
their ages will be 3:2, because the teacher will be
 and the student will be , and the
fraction  equals to the fraction .

So the equation is:

 = 

Solve that and get X = 15, and so the teacher is 30.

Edwin