What subjects do three teachers teach in primary school?

Mr. Wang is younger than the teacher who teaches art, which means that Mr. Wang does not teach art.

The teacher who teaches art is younger than Miss Li, which shows that Miss Li doesn't teach art. ..

So teacher Zhang teaches art.

Teacher Zhang is older than the music teacher, that is, the art teacher is older than the music teacher.

The teacher who teaches art is younger than Miss Li, which shows that the music teacher is not Miss Li, but Miss Wang.

So Mr. Wang teaches music.

Combining the following two conditions, Mr. Li teaches calligraphy.