InterviewSolution
Saved Bookmarks
InterviewSolution
| 1. |
The number of ways in which a score of 11 can be made from a throw by three persons,each throwing a single die once, isA. 45B. 18C. 27D. none of these |
|
Answer» Required number of ways = Coeff. of `x^(11)" in "(x+x^(2)+......+x^(6))^(3)` = Coeff. of `x^(8)" in "(1+x+x^(2)+......+x^(5))^(3)` = Coeff. of `x^(8)" in "((1-x^(6))/(1-x))^(3)` Coeff. of `x^(8)" in "(1-x^(6))^(3)(1-x)^(-3)` = Coeff. of `x^(8)" in "(1-""^(3)C_(1)x^(6)+....)(1-x)^(-3)` = Coeff. of `x^(8)" in "(1-x)^(-3)-""^(3)C_(1)."Coff. of "x^(2)" in "(1-x)^(-3)` `=""^(8+3-1)C_(3-1)-""^(3)C_(1).""^(2+3-1)C_(3-1)=""^(10)C_(2)-3xx""^(4)C_(2)=27` |
|