MEDIUM
JEE Main/Advance
IMPORTANT
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If a,b,c are in A.P. and a2,b2,c2 are in H.P. Then, which is of the following is/are possible?

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Important Questions on Progression and Series

EASY
JEE Main/Advance
IMPORTANT
The corresponding first and the 2n-1th terms of an A.P., a G.P. and an H.P. are equal. If their nth terms are a,b and c respectively, then
HARD
JEE Main/Advance
IMPORTANT
Let a,b,c,d be four distinct real numbers in A. P. Then the smallest positive value of k satisfying 2a-b+kb-c2+c-a3=2a-d+b-d2+c-d3 is 
HARD
JEE Main/Advance
IMPORTANT
Let the fourth term of an arithmetic progression be 6 and  mth term be 18. If A.P. has integral terms only then the numbers of such A.P.s is
MEDIUM
JEE Main/Advance
IMPORTANT
The 5th and 8th terms of a geometric sequence of real numbers are 7! and 8!, respectively. If sum of first n terms of the G.P. is 2205, then n equals
HARD
JEE Main/Advance
IMPORTANT
Let a1, a2, a3,...., a101 are in G.P. with a101=25 and i=1201ai =625. Then the value of i=12011ai equals
MEDIUM
JEE Main/Advance
IMPORTANT
For a, b>0, let 5a-b, 2a+b, a+2b be in A.P. and b+12, ab+1, a-12 are in G.P., then the value of  a-1+b-1 is
MEDIUM
JEE Main/Advance
IMPORTANT
Let a+ar1+ar12+....+ and a+ar2+ar22+....+ be two infinite series of positive numbers with the same first term. The sum of the first series is r1 and the sum of the second series is r2. Then the value of r1+r2 is