1. The problem asks which type of graph best shows the number of books in each bedroom. 2. To represent quantities for different categories (bedrooms), a graph that clearly compares amounts is needed. 3. A bar graph is ideal for showing quantities across categories because it uses bars of different lengths to represent values. 4. A double bar graph is used to compare two sets of data side by side, which is unnecessary here. 5. A line graph is best for showing trends over time, not categorical quantities. 6. A circle graph (pie chart) shows parts of a whole, which is less effective for comparing individual category counts. 7. Therefore, the best choice is a bar graph to show the number of books in each bedroom clearly and simply. Final answer: bar graph