1,3,9 can be terms of (A) an A.P. out not of a G.P (B) G.P. but not of an A.P. (C) A.P. and G.P both (D) neither A.P nor G.P

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.

If p ,q ,a n dr are in A.P., then which of the following is/are true? pth, qth, and rth terms of A.P. are in A.P. pth, qth, rth terms of G.P. are in G.P. pth, qth, rth terms of H.P., are in H.P. none of these

If a,b,c are non zero real numbers such that 3(a^2+b^2+c^2+1)=2(a+b+c+ab+bc+ca) then a,b,c are in (A) A.P. only (B) G.P. only (C) A.P., G.P., and H.P. (D) A.P. and G.P.both

If a,b,c are in A.P. as well as in G.P. then

If a-b,ax-by,ax^2-by^2a,b!=0) are in G.P., then x,y (ax-by)/(a-b) are in (A) A.P. only (B) G.P.only (C) A.P., G.P. (D) A.P., and G.P and H.P