The freshman class of East High School has 88 students. Due to resource limitations, the freshman class must be divided up into 4 individual physical education classes that occur at different times of the day, with no more than 22 students per class. How many different combinations of students are possible in the 4 physical education classes?

1 answer

To determine the number of different combinations of 88 students divided into 4 classes with no more than 22 students in each class, we must consider how we can divide the students into four groups of up to 22 students each while keeping the maximum limit of 22 students per group.

Step 1: Class Sizes

We denote the size of each class as \( x_1, x_2, x_3, x_4 \), where \( x_i \) represents the number of students in class \( i \). The constraints we have are:

\[ x_1 + x_2 + x_3 + x_4 = 88 \]

with

\[ 0 \leq x_i \leq 22 \quad \text{for } i = 1, 2, 3, 4. \]

Step 2: Count the Combinations

We need to find the number of non-negative integer solutions to the equation \( x_1 + x_2 + x_3 + x_4 = 88 \) given the constraints.

Using the principle of Stars and Bars, the total number of non-negative integer solutions without constraints would be given by:

\[ \binom{n + k - 1}{k - 1} \]

where \( n = 88 \) (the total number of students) and \( k = 4 \) (the number of classes).

Step 3: Introduction of Constraints

However, we need to apply the "stars and bars" method while accounting for the upper limit of 22 students per class.

  1. Let's define our classes by letting \( y_i \) represent the actual number of students in the group \( x_i \):

    \[ y_i = x_i - 22 \Rightarrow x_i = y_i + 22. \]

    The new equation becomes:

    \[ (y_1 + 22) + (y_2 + 22) + (y_3 + 22) + (y_4 + 22) = 88 \]

    Simplifying leads us to:

    \[ y_1 + y_2 + y_3 + y_4 = 88 - 88 = 0. \]

    Therefore, \( y_1 = y_2 = y_3 = y_4 = 0 \).

  2. This constraint means that all \( x_i \) must actually take on values between 0 and 22, and since all classes must be filled to make 88, we find it is impossible for 4 classes to reach 88 without violating the maximum student count.

Step 4: Conclusion

Given that 88 exceeds the maximum total limits of \( 4 \times 22 = 88\), any configuration would require some classes to exceed 22 students, violating the constraints.

Thus, the total number of combinations of students into 4 physical education classes compliant with the requirements is:

\[ \boxed{0}. \]

There are no valid arrangements that fit the conditions given.