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Lachlan1996 Group Title

Help with mathematical combinations please. Points A, B, C, D, E, F, G, H, and I are arranged in two rows such that we have A - B - C - D - E and F - G - H - I How many triangles can be formed having vertices chosen from these points? How many of these triangles have the point A as one of their vertices?

  • one year ago
  • one year ago

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  1. Lachlan1996 Group Title
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    Sorry it is A - B - C - D - E F - G - H - I

    • one year ago
  2. Lachlan1996 Group Title
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    Awesome thank you for visiting unklerhaukus!!!

    • one year ago
  3. UnkleRhaukus Group Title
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    |dw:1360476356312:dw|

    • one year ago
  4. Lachlan1996 Group Title
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    Yes they are to act as the vertices of triangles.

    • one year ago
  5. UnkleRhaukus Group Title
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    so either two points are from the top line (and one from the bottom line) or one point is from the top line (and two from the bottem line)

    • one year ago
  6. Lachlan1996 Group Title
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    Hmm i see, let me try that, i wasnt sure how to interpret it.

    • one year ago
  7. UnkleRhaukus Group Title
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    because if all three points were on the same line , you couldn't make a triangle

    • one year ago
  8. Lachlan1996 Group Title
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    Yes that appears to work, 5C1 x 4C2 and 5C2 x 4C1 which adds to 70

    • one year ago
  9. Lachlan1996 Group Title
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    Though can I ask how you determine how to do these questions? I havent really got a problem solving type of mind, so i find it difficult to think laterally.

    • one year ago
  10. UnkleRhaukus Group Title
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    \[^nC_k = \frac{n!}{k!(n-k)!}\]

    • one year ago
  11. Lachlan1996 Group Title
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    No i understand the general formula of the combination theory. I just often have difficulty understanding how I am meant to approach the question, what guidelines I need to follow.

    • one year ago
  12. Lachlan1996 Group Title
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    Once you had explained those guidelines i knew exactly what to do, i just dont know how to determine the parameters to follow.

    • one year ago
  13. UnkleRhaukus Group Title
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    i like to start with a picture usually

    • one year ago
  14. Lachlan1996 Group Title
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    Are there any other tricks you can use to figure out whats going on? or is it just trying to pull apart the question, and making assumptions to rules.

    • one year ago
  15. UnkleRhaukus Group Title
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    im not sure how to answer that,

    • one year ago
  16. Lachlan1996 Group Title
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    Ah well, im sure i'll just have to pick it up as I go. You've helped enough already. Thank you very much for the assistance. I wish you a good afternoon. Thank you for the help mate, I appreciate the effort :) Have a good one mate, and stay well!

    • one year ago
  17. UnkleRhaukus Group Title
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    sometimes rewriting the question into a simpler form can help

    • one year ago
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