Why does God not answer my supplication, and does this mean that He is angry with me, and what should I do for Him to be pleased with me?

Success in exams does not depend merely on reliance upon Allah (tawakkul) and supplication (du'a), but rather one must take the necessary means and exert effort in studying. The response to supplication is not limited to the fulfillment of what is requested; Allah may avert evil or save the reward for the Day of Judgment. The servant must repent from sins and observe the obligatory duties and increase in supererogatory acts, for sins may be a cause for the withholding of an answer. One must continue to supplicate while taking the necessary means, relying upon Allah, and being content with His decree.