Anna is making gingerbread cookies. She gives 6 of them red hats, 9 of them blue boots, and 3 of them both red hats and blue boots. What percentage of the gingerbread men have red hats? Let's think first. Chain of thought:
The first step to find the total number of gingerbread men is to add the number with each decoration: 6 men + 9 men = 15 men. Then subtract the number of gingerbread men with both decorations to find the total number of gingerbread men: 15 men - 3 men = 12 men. Then divide the number of gingerbread men with red hats by the total number and multiply by 100% to express the answer as a percentage: 6 men / 12 men * 100% = 50%.
Therefore, the answer is 50.