It is not possible to grant extra time for answering to individual students for general exams in EXAM. The exam times in the University of Jyväskylä EXAM is 50 minutes, 110 minutes, 170 minutes, or 230 minutes. 

The simplest solution is to create a personal exam for the student with a longer exam time. If there is a general exam for the course, you can make a new copy of it as a personal exam, changing only the duration of the exam and adding the student as a participant.

If the exam is a so-called long exam (230 minutes), no extra time can be granted in EXAM but you can divide the questions of the exam and create eg. two shorter personal exams for the student.