Let the sum of first n1, first n2 and first n3 terms of an AP be denoted by S1, S2 and S3 respectively. Then the value of S1(n2-n3)/n1 +... View Article
The sum of the products taken two at a time of the numbers 1, 2, 22,....2n-2, 2n-1 is (1) (1/3)22n - 22n -2n + (â…”) (2) (1/3)22n + 22n -(â…”)... View Article
Let f(n) = [(n+50)/100] where [n] denotes the integral part of x . Then (1) ∑n = 1100 f(n) = 51 (2) ∑n = 50100 f(n) = 51 (3) ∑n = 11000... View Article
Let ai + bi = 1 (i = 1,2,..n) and a = (1/n)(a1 + a2 +....+an) , b = (1/n)(b1 + b2 +....+bn) then a1b1 + a2b2 + ...anbn is equal to (1) nab... View Article