Is it permissible to complete one's studies in a mixed institute, when there is only one female student in the classroom?

Mixing between the sexes in universities and the like is forbidden. A Muslim must avoid places of mixing because they are among the snares of Satan. If you are able, in your current studies, to lower your gaze and avoid temptation, then there is no blame upon you, and you must strive to reduce evil and choose righteous company. However, if your staying will lead to temptation, then it is not permissible for you to stay, and you must complete your studies in another institute, for preserving one's religion takes precedence over every other interest.