Math Problem Statement

generate the list of 6 digit numbers containing the numbers 2, 3, 4, 6, 7, 8, 9 with 3 as the first digit and 2 as the fourth digit without repeating the same number

Solution

To generate a list of 6-digit numbers that contain the digits 2, 3, 4, 6, 7, 8, 9, with the digit 3 as the first digit and the digit 2 as the fourth digit, and without repeating any digit, we proceed as follows:

Step-by-step process:

  1. Digits pool: The available digits are 2, 3, 4, 6, 7, 8, 9.
  2. Conditions:
    • The first digit must be 3.
    • The fourth digit must be 2.
    • No digit is repeated in the number.

Format of the number: 3 _ _ 2 _

So, the number has the following structure:

  • First digit: 3 (fixed)
  • Fourth digit: 2 (fixed)
  • The remaining digits (positions 2, 3, 5, and 6) must be chosen from the set {4, 6, 7, 8, 9}, without repetition.

Choices for the other positions:

  • Second digit: Choose from {4, 6, 7, 8, 9} (5 possibilities).
  • Third digit: Choose from the remaining 4 digits after selecting the second digit.
  • Fifth digit: Choose from the remaining 3 digits after selecting the second and third digits.
  • Sixth digit: Choose from the remaining 2 digits after selecting the second, third, and fifth digits.

List Generation:

Let me generate this list:

  1. 346278
  2. 346279
  3. 346287
  4. 346289
  5. 346297
  6. 346298
  7. 347268
  8. 347269
  9. 347286
  10. 347289
  11. 347296
  12. 347298
  13. 348267
  14. 348269
  15. 348276
  16. 348279
  17. 348296
  18. 348297
  19. 349267
  20. 349268
  21. 349276
  22. 349278
  23. 349286
  24. 349287
  25. 364278
  26. 364279
  27. 364287
  28. 364289
  29. 364297
  30. 364298
  31. 367248
  32. 367249
  33. 367284
  34. 367289
  35. 367294
  36. 367298
  37. 368247
  38. 368249
  39. 368274
  40. 368279
  41. 368294
  42. 368297
  43. 369247
  44. 369248
  45. 369274
  46. 369278
  47. 369284
  48. 369287

These are all the possible 6-digit numbers meeting the criteria.

Would you like further details or have any questions?

Here are 5 questions related to this:

  1. How would the list change if we added another condition, such as a fixed second digit?
  2. How many possible numbers would exist if repetitions were allowed?
  3. What if we limited the available digits to only 6 instead of 7?
  4. How would the problem change if the fourth digit were not fixed to 2?
  5. How can you generalize this process for larger sets of digits?

Tip: When generating combinations with fixed digits, it's helpful to systematically reduce the available pool for each remaining position to avoid repetition errors.

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Math Problem Analysis

Mathematical Concepts

Combinatorics
Permutations

Formulas

Permutation formula P(n, r) = n! / (n - r)!

Theorems

Fundamental principle of counting

Suitable Grade Level

Grades 9-12