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Question #40611
The Question
Let be the rank of the word "IITJEE" when all words formed by permutations of its letters are arranged as in a dictionary. Let Find the value of .
Options
- A.
- B.
- C.
- D.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Specialist
Targeted practice for niche, high-difficulty concepts that frequently appear in JEE Advanced exams.
Concepts Behind This Question
Rank of a Word|Indeterminate Forms|Trigonometric Standard Limits
Why This Question Is Tricky
Common Mistakes
This question tests the synthesis of combinatorics (dictionary rank with repeating letters) and calculus (indeterminate forms requiring Taylor series expansion).
The trap lies in two places: First, students often miscalculate the rank by mishandling the permutations of identical letters (e.g., forgetting to divide by for 'E' or 'I', leading to and the distractor ).
Second, the limit requires expanding trigonometric functions to the third power (); using only the first-order approximation () leads to a form that incorrectly evaluates to , forcing them to re-evaluate using higher-order terms or L'Hôpital's rule.
Quick Facts About This Question
Question Information
| Subject | Mathematics |
| Chapter | Permutations and Combinations - Class 11 |
| Concept | Rank of a Word |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |