Stacy is a high school Calculus teacher. She assigns 45 problems for homework. There are twice as many multiple choice problems as free response, and 7 more free response than true/false. How many true/false questions are there? Let's think first. Chain of thought:
Let x represent the number of true / false questions. Free response:x + 7. Multiple choice: 2(x + 7) = 2x + 14. Total:x + x + 7 + 2x + 14 = 45. 4x + 21 = 45. 4x = 24. x = 6 true / false questions.
Therefore, the answer is 6.