If `(l+mx)/(l-mx)= (m+nx)/(m-nx)=(n+px)/(n-px),x!=0`. Then the number l,m,n and p are in (A) A.P. (B) G.P. (C) H.P. (D) none of these

If a_n= int_0^pi(sin(2n-1)x)/sinx dx, then a_1a_2a_3 are in (A) A.P. (B) G.P. (C) H.P. (D) none of these

If a,b,c are in A.P ,then 3^(a),3^(b),3^(c) shall be in (A) A.P (B) G.P (C) H.P (D) None of these

If the numbers p,q,r are in A.P. then m^(7p), m^(7q), m^(7r)(mgt0) are in (A) A.P. (B) G.P. (C) H.P. (D) none of these

If a,b,c are proper fractiion are in H.P. and x sum_(n=1)^oo a^n, y=sum_(n=1)^oo b^n, z= sum_(n=1)^oo c^n then x,y,z are in (A) A.P. (B) G.P. (C) H.P. (D) none of these

If the square of differences of three numbers be in A.P., then their differences re in (A) A.P. (B) G.P. (C) H.P. (D) none of these

If a,b,c,d are distinct positive then a^n/b^ngtc^n/d^n for all epsilon N if a,b,c,d are in (A) A.P. (B) G.P. (C) H.P. (D) none of these

I a_n= int_0^(pi/2) (1-cos2nx)/(1-cos2x)dx then a_1,a_2,a_3,………,a_n are in (A) A.P. only (B) G.P.only (C) H.P. only (D) A.P., G.P. and H.P.

If f(x)=((x^(l))/(x^(m)))^(l+m)((x^(m))/(x^(n)))^(m+n)((x^(n))/(x^(l)))^(n+l) then f'(x) is equal to (a) 1 (b) 0 (c) x^(l+m+n) (d) none of these

If a_n= the digit at units palce in the number o 1!+2!+3!+……….n! for nge4 the a_4, a_5, a_6, ……… are in (A) A.P. only (B) G.P. only (C) A.P. and G.P. only (D) A.P., G.P. and H.P.

The equation of the plane through the intersection of the plane a x+b y+c z+d=0\ a n d\ l x+m y+n+p=0 and parallel to the line y=0,\ z=0. (A) (b l-a m)y+(c l-a n)z+d l-a p=0 (B) (a m-b l)x+(m c-b n)z+m d-b p=0 (c) (n a-c l)d+(b n-c m)y+n d-c p=0 (D) None of these