MEDIUM
JEE Main
IMPORTANT
Earn 100

If n arithmetic means are inserted between a and 100 such that the ratio of the first mean to the last mean is 1:7 and a+n=33, then the value of n is

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Important Questions on Sequences and Series

HARD
JEE Main
IMPORTANT
Let for n=1,2,,50, Sn be the sum of the infinite geometric progression whose first term is n2 and whose common ratio is 1n+12. Then the value of 126+n=150Sn+2n+1-n-1 is equal to
HARD
JEE Main
IMPORTANT
Let ann=0 be a sequence such that a0=a1=0 and an+2=2an+1-an+1 for all n0. Then, n=2an7n is equal to
MEDIUM
JEE Main
IMPORTANT
The sum of the infinite series 1+56+1262+2263+3564+5165+7066+ is equal to:
EASY
JEE Main
IMPORTANT
Let 3, 6, 9, 12,  upto 78 terms and 5, 9, 13, 17,  upto 59 terms be two series. Then, the sum of the terms common to both the series is equal to ______.
HARD
JEE Main
IMPORTANT
Let a,b be two non-zero real numbers. If p and r are the roots of the equation x2-8ax+2a=0 and q and s are the roots of the equation x2+12bx+6b=0, such that 1p,1q,1r,1 s are in A.P., then a-1-b-1 is equal to _____ .
MEDIUM
JEE Main
IMPORTANT
Let a1=b1=1,an=an-1+2 and bn=an+bn-1 for every natural number n2. Then n=115an·bn is equal to _____ .
MEDIUM
JEE Main
IMPORTANT
Consider two G.Ps. 2,22,23, and 4,42,43, of 60 and n terms respectively. If the geometric mean of all the 60+n terms is 22258, then k=1nkn-k is equal to: