{"id":"cbest-free","timeLimitSec":648,"questions":[{"id":"cbf-01","section":"reading","q":"Many schools now plant small vegetable gardens. Students who grow vegetables are more likely to taste them, and teachers use the beds to teach measurement, life cycles and weather. The gardens cost little, because parents often donate seeds and tools. Which statement best expresses the main idea of the passage?","options":["Weather is the hardest subject to teach outdoors.","Students only eat vegetables that they have grown.","School gardens are a low-cost way to support learning.","Parents should donate more seeds and tools to schools."],"answer":2,"explain":"Every sentence supports one point: gardens help students learn and cost little. The other choices are either details or claims the passage does not make."},{"id":"cbf-02","section":"math","q":"A class library has 240 books, and 15% of them are biographies. How many biographies are in the library?","options":["36","40","24","30"],"answer":0,"explain":"15% of 240 = 0.15 × 240 = 36. A quick check: 10% is 24 and 5% is 12, and 24 + 12 = 36."},{"id":"cbf-03","section":"reading","q":"The city council voted to extend library hours on weekdays. Supporters argued that working parents could not reach the library before it closed at 5 p.m. Since the change, evening visits have doubled. Which conclusion is best supported by the passage?","options":["The council will reduce library hours next year.","The later hours met a real need of some residents.","Working parents no longer read on weekends.","Libraries in every city should stay open until midnight."],"answer":1,"explain":"Evening visits doubled after the change, which supports the idea that people needed later hours. The other choices go beyond what the passage says."},{"id":"cbf-04","section":"math","q":"A student reads 18, 25, 22 and 31 pages on four nights. What is the mean (average) number of pages per night?","options":["24","96","23.5","25"],"answer":0,"explain":"Add the pages: 18 + 25 + 22 + 31 = 96. Divide by the 4 nights: 96 ÷ 4 = 24. (23.5 is the median, not the mean.)"},{"id":"cbf-05","section":"math","q":"A rectangular bulletin board is 4 feet tall and 6 feet wide. How many feet of border trim are needed to go all the way around it?","options":["10 feet","48 feet","24 feet","20 feet"],"answer":3,"explain":"The trim goes around the edge, so you need the perimeter: 2 × (4 + 6) = 20 feet. 24 would be the area in square feet."}]}