In a sequence of (4n + 1) terms the first (2n + 1) terms are in AP whose common difference is 2, and the last (2n + 1) terms are in GP whose common ratio is 0.5. If the middle terms of the AP and GP are equal, then the middle term of the sequence is

In a sequence of 21 terms the first 11 terms are in A.P.with common difference 2. and the lastterms are in G.P.with common ratio 2. If the middle tem of the A.P.is equal to themiddle term of the G.P.,then the middle term of the entire sequence is

In a sequence of 21 terms first 11 terms are in A.P. with common difference 2 and last 11 terms are in P with common ratio 2. If middle term of A.P. is equal to middle term of G.P. then, middle term in the complete sequence is 10 (1-211 B) 210-1 20 2 10 1-211 1-2 (C) 1024 + 10 (D) 210-1 a, b, c are real nymbers forming an A.P. and 3 a, 2+ b, 3+ c are in GP, then minimum value of

Sum of first n terms of an A.P. whose last term is l and common difference is d, is

If n^(th) term of A.P is 2n+3, then common difference is

If S_(n) denotes the sum of n terms of an A.P. whose common difference is d and first term is a,find S_(n)-2S_(n-1)+S_(n-2)

If a is the first term and d is the common difference of an AP, then the (n+1) th term of the AP is _____.

The sum of first n terms of an A.P. is 5n ^(2)+ 4n, its common difference is :

The sum of n terms of an AP is 3n^(2)+ nand its common difference is 6, then find its first term.