Piece of cake, here:
1) In order to delay sitting for the exam, he deceived the teacher by telling her that she is ill.
2) He deceives the teacher by telling her that he is ill, because he wants to postpone taking the exam until next Wednesday.
3) Can I postpone my exam to the next session, which will be held next Wednesday, instead of taking the exam during the next session, which is tommorow?
If it has happened, then use "deceived" and, if it's in the present tense, use "deceives"
Student or Learner