Sí, es posible, y funciona. Echa un vistazo a la siguiente prueba:
CREATE TABLE a(a INT, b INT);
INSERT INTO a VALUES (1, 1);
INSERT INTO a VALUES (1, 2);
INSERT INTO a VALUES (1, 3);
INSERT INTO a VALUES (1, 4);
INSERT INTO a VALUES (1, 5);
INSERT INTO a VALUES (1, 6);
INSERT INTO a VALUES (2, 1);
INSERT INTO a VALUES (2, 2);
INSERT INTO a VALUES (2, 3);
INSERT INTO a VALUES (2, 4);
INSERT INTO a VALUES (2, 5);
INSERT INTO a VALUES (2, 6);
SELECT a.a, a.b, (a/b) FROM a ORDER BY (a/b);
+------+------+--------+
| a | b | (a/b) |
+------+------+--------+
| 1 | 6 | 0.1667 |
| 1 | 5 | 0.2000 |
| 1 | 4 | 0.2500 |
| 2 | 6 | 0.3333 |
| 1 | 3 | 0.3333 |
| 2 | 5 | 0.4000 |
| 1 | 2 | 0.5000 |
| 2 | 4 | 0.5000 |
| 2 | 3 | 0.6667 |
| 2 | 2 | 1.0000 |
| 1 | 1 | 1.0000 |
| 2 | 1 | 2.0000 |
+------+------+--------+
SELECT a.a, a.b FROM a ORDER BY (a/b); devolvería los mismos resultados.
