Does leaving some pages of the book and relying on God affect the ability to properly rely [on Him] when questions from those pages come in the exam?

Trust in Allah (Tawakkul) is an act of the heart that relies on trusting in Allah and being content with His decree. It differs from taking measures (Asbab), which is an outward act performed by the limbs. Taking measures is necessary and is a requirement of Tawakkul; it does not contradict it. Whoever abandons taking measures is one who pretends to rely on Allah while being helpless. Therefore, combining inner trust in Allah with undertaking outward measures is the correct approach.