Step 1: Calculate the total number of different possible answers a student can give.
- Since there are 3 questions each with 4 options, the total possible combinations are \(4^3 = 64\).
Step 2: Adjust for the constraint that no student can answer all questions correctly.
- Subtract the one combination where all answers are correct, leaving \(64 - 1 = 63\) possible ways to answer.
Step 3: Given that no two students answer identically, the maximum number of students who could have written the test without any of them having all correct answers is therefore \(63\).