30 Points. Directions: Type your response in the box.
Martha recorded the ratio of students and teachers at all the middle schools in the Timber Creek school district. The list is shown below.

1. 20 students : 2 teachers
2. 1 teacher per 15 students
3. 1 teacher per 10 students
4. 40 students : 4 teachers
5. 5 teachers per 40 students

Part A: Identify the unir rates and ratios that are equivalent.
Part B: Give another unit rate or ratio that is not on the list but equivalent to the ones from Part A. Explain why these are equivalent.