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Question #40565
The Question
Let be the set of all distinct permutations of the multiset . For each permutation , a plane is defined by the equation . Let be the unique point of intersection of all the planes for . Let and be the number of distinct permutations of the letters of the words 'TO', 'JEE', and 'NOON' respectively. A plane contains the origin , the point , and the point . A line lies in the plane , passes through the origin, and is perpendicular to the line . If the direction ratios of are where are coprime integers and , find the value of .
Options
- A.
26
- B.
78
- C.
546
- D.
6
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Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Monster
Ultra-high difficulty questions designed to test your limit, stamina, and deep conceptual understanding.
Concepts Behind This Question
Permutations of Identical Objects|Line lying in a plane|Variable plane intercepts
Why This Question Is Tricky
Common Mistakes
This question tests the student's ability to handle a dynamically generated family of planes based on combinatorial states, coupled with 3D analytical geometry.
The primary trap lies in the variable plane intercepts: students often fail to recognize the symmetry of the permutation set, which guarantees a unique common intersection point on the line .
Instead, they might erroneously pick a single plane from the family (e.g., ) and proceed, leading to an incorrect direction vector.
Additionally, the problem requires precise calculation of multiset permutations and multiple cross products, punishing those who confuse the normal of a plane with a line lying within it.
Quick Facts About This Question
Question Information
| Subject | Mathematics |
| Chapter | Permutations and Combinations - Class 11 |
| Concept | Permutations of Identical Objects |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |