LinkBack URL
About LinkBacksProve that the total number of selectionsthat can be made out of the letters "DADDY DID A DEADLY DEED" is 1919.
does anyone have the solution to this??
-thank you
Please tell us what is meant by a selection?Originally Posted by blackhat98
POST SCRIPT:
I made a guess as to what this question means.
If one expands^2 \left( {1 + x + x^2 } \right)\left( {\sum\limits_{k = 0}^3 {x^k } } \right)^2 \left( {\sum\limits_{k = 0}^9 {x^k } } \right))
we get a polynomial of degree 19.
Each coefficient in the expansion tell the number of possible selections.
For example: the term in the expansiontells us that there are 191 ways to select nine items from that list.
If we sum all the coefficients we get.
But that includes the empty selection.
Remove it and there is
thank you Plato....Please tell us what is meant by a selection?
POST SCRIPT:
I made a guess as to what this question means.
If one expands
we get a polynomial of degree 19.
Each coefficient in the expansion tell the number of possible selections.
For example: the term in the expansion
If we sum all the coefficients we get
But that includes the empty selection.
Remove it and there is
  |
