Total quarts of tea available = 15 1/2
In improper fraction, that is:

Each teacher will get = 7/8 quarts
To find the number of teachers, we divide total quarts of tea available by amount each teacher gets. Thus, we can:

To divide a fraction by another fraction, we multiply the fraction by the denominator fraction's reciprocal and get our answer to be (shown below):

Disregarding the fractional amount,
We can say, that 17 teachers can get 7/8 quarts each.
Answer: 17 teachers