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We need to determine whether at least two students had the same number of correct answers on a 20-question test.

Step 1: Understanding the Problem
Each student’s score is a whole number between 0 and 20. We need to check if any two students had the same score.
This is a pigeonhole principle question: If we have more students than possible distinct scores, at least two must share the same score.

Step 2: Evaluating Statement (1)
(1) Each student answered an even number of questions correctly.
- Possible scores are limited to even numbers: {0, 2, 4, ..., 20}.
- There are 11 possible scores.

However, we don’t know how many students are in the class. If there are more than 11 students, the pigeonhole principle would guarantee a duplicate score. If there are 11 or fewer, we cannot be sure.
Insufficient.

Step 3: Evaluating Statement (2)
(2) There are more than 11 students in the class.
- The number of students is at least 12.
- However, this doesn’t tell us about the possible scores they achieved. If all 21 scores (0 to 20) were available, we could have 12 different scores without duplication.
Insufficient.

Step 4: Evaluating Statements Together
- From (1), possible scores are only 11 different even numbers.
- From (2), there are more than 11 students.
- Since there are more students than available distinct scores, at least two must share the same score.

Together, they are sufficient.

Final Answer: (C) Together sufficient, but neither alone.
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Question: Did two students have same number of correct answers?

Statement 1: Each student answered an even number of questions correctly.

i.e. students answered {0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20} - 11 total choices
but we don't know how many students the class has therefore
NOT SUFFICIENT

Statement 2: There are more than 11 students in the class.
But we don't know scoring method hence
NOT SUFFICIENT

Combining the statements
more than 11 students and only 11 possible outcomes of correct answers hence definitely atleast two marked the same number of correct answers hence
SUFFICIENT

Answer: Option C


Related Video:


Bunuel
All of the students in a certain class took a test consisting of 20 questions. Did at least two students have the same number of correct answers on the test?

(1) Each student answered an even number of questions correctly.
(2) There are more than 11 students in the class.
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