If in a progression `a_1, a_2, a_3,.......... e tc dot,(a_r-a_(r+1))` bears a constant ratio with `a_rxxa_(r+1)` , then the terms of the progression are in a. A.P b. G.P. c. H.P. d. none of these

If the pth, qth, rth, and sth terms of an A.P. are in G.P., then p-q ,q-r ,r-s are in a. A.P. b. G.P. c. H.P. d. none of these

If a ,b ,c are in A.P., the a/(b c),1/c ,1/b will be in a. A.P b. G.P. c. H.P. d. none of these

If a^2+b^2,a b+b c and b^2+c^2 are in G.P., then a ,b ,c are in a. A.P. b. G.P. c. H.P. d. none of these

If a x^3+b x^2+c x+d is divisible by a x^2+c ,t h e na ,b ,c ,d are in a. A.P. b. G.P. c. H.P. d. none of these

If cos2B=(cos(A+C))/("cos"(A-C)) , then tanA ,t a n B ,tanC are in (a)A.P. (b) G.P. (c) H.P. (d) none of these

If tanbeta=2sinalphasingammacos e c(alpha+gamma), then cotalpha,cotbeta,cotgamma are in (a)A.P. (b) G.P. (c) H.P. (d) none of these

If a_1, a_2, a_3(a_1>0) are three successive terms of a G.P. with common ratio r , for which a_3>4a_2-3a_1 holds true is given by a. 1ltrlt-3 b. -3ltrlt-1 c. r gt3 or rlt1 d. none of these

If the coefficients of the rth, (r+1)t h ,(r+2)t h terms is the expansion of (1+x)^(14) are in A.P, then the largest value of r is.

In a sequence of (4n+1) terms, the first (2n+1) terms are n A.P. whose common difference is 2, and the last (2n+1) terms are in G.P. whose common ratio is 0.5 if the middle terms of the A.P. and LG.P. are equal ,then the middle terms of the sequence is (n .2 n+1)/(2^(2n)-1) b. (n .2 n+1)/(2^n-1) c. n .2^n d. none of these

Consider an A.P. a_1, a_2, a_3,......... such that a_3+a_5+a_8=11 and a_4+a_2=-2, then the value of a_1+a_6+a_7 is (a). -8 (b). 5 (c). 7 (d). 9