A school has 100 students distributed among to standards.
Based on this, which one of the following statements is always correct?
- AThere are at least 10 students who belong to the same standard.
- BThere is at least one student in each standard.
- CThere are at most 10 students in standard.
- DThe total number of students from to standards is at least 50.
Solution & Step-by-step Explanation
The question asks us to identify a statement that is guaranteed to be true when 100 students are distributed among 10 different standards (from 1 to 10).
Applying the Pigeonhole Principle
This problem can be solved using the Pigeonhole Principle. In this scenario:
- Pigeons: The 100 students.
- Pigeonholes: The 10 standards.
The generalized Pigeonhole Principle states that if items are placed into containers, then at least one container must hold at least items.
Calculating Minimum Students Per Standard
We apply the principle with students and standards:
Minimum number of students in at least one standard =
Calculation:
Identifying the Always Correct Statement
The calculation shows that there must be at least one standard containing a minimum of 10 students. This directly confirms the first option.
Therefore, the statement "There are at least 10 students who belong to the same standard" is always correct.
Analyzing Why Other Options Are Not Always Correct
Let's examine why the other options might not always hold true:
- Option 2: It's possible all 100 students are in just one or a few standards, leaving others empty.
- Option 3: All 100 students could be concentrated in the 10 standard alone.
- Option 4: The students could all be in standards 6 to 10, making the total for 1 to 5 zero.