Usually, the time divided for each section or passage given is 20 minutes per passage. But if you are a beginner then try to time yourself for 20 minutes for each passage, and with time just increase your pace and keep decreasing the time taken to find the answers for the first and second passages. Because the last passage requires more time and effort to locate the correct answer. Even if you find a question difficult, don't take more than a minute to answer it. Return to the concerned question later.