Final answer:
The greatest number of students that can be placed in one algebra class out of 3 is 35.
Step-by-step explanation:
To find the greatest number of students that can be placed in one class, divide the total number of students (100) by the maximum number of students per class (35). This gives us a quotient of 2.857, which means that we can have 2 classes with 35 students and 1 class with 30 students. Therefore, the greatest number of students that can be placed in one class is 35 (option B).