InterviewSolution
Saved Bookmarks
| 1. |
Let `a_(1)+a_(2)+a_(3), . . . ,a_(n-1),a_(n)` be an A.P. Statement -1: `a_(1)+a_(2)+a_(3)+ . . . +a_(n)=(n)/(2)(a_(1)+a_(n))` Statement -2 `a_(k)+a_(n-k+1)=a_(1)+a_(n)" for "k=1,2,3, . . . ,` nA. Statement -1 is true, Statement -2 is True, Statement -2 is a correct explanation for Statement for Statement -1.B. Statement -1 is true, Statement -2 is True, Statement -2 is not a correct explanation for Statement for Statement -1.C. Statement -1 is true, Statement -2 is False.D. Statement -1 is False, Statement -2 is True. |
|
Answer» Correct Answer - A Let `S_(n)=a_(1)+a_(2)+a_(3)+ . . . +a_(n-1)+a_(n)`. Then, `S_(n)=a_(n)+a_(n-1)+a_(n-2)+ . . . +a_(2)+a_(1)` `rArr" "2S_(n)=n(a_(1)+a_(n))" [Using statement-2]"` `rArr" "S_(n)=(n)/(2)(a_(1)+a_(2))` So, statement -2 correct explanation for statement -1. |
|