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JEE Main/Advance
IMPORTANT
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Let Sn=k=14n-1kk+12 k2. Then Sn can take value s

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Important Questions on Progression and Series

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JEE Main/Advance
IMPORTANT
Let Sk, k=1,2...., 100, denote the sum of the infinite geometric series whose first term is k-1k ! and the common ratio is 1k, then the value of 1002100 !+k=1100k2-3k+1Sk is
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JEE Main/Advance
IMPORTANT
Let a1, a2, a3,...., a11 be real numbers satisfying a1=15, 27-2a2>0 and ak=2ak-1-ak-2 for k=3, 4,..., 11. If a12+a22+....+a11211=90, then the value of a1+a2+...+a1111 is equal to            .
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JEE Main/Advance
IMPORTANT
Let a1, a2, a3,...a100 be an arithmetic progression with a1=3  and Sp=i=1pai , 1p100. For any interger n with 1n20, let m=5n. If SmSn does not depend on n, then a2 is               .
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JEE Main/Advance
IMPORTANT
A pack contains n cards numbered from 1 to n. Two consecutive numbered cards are removed from the pack and the sum of the numbers on the remaining cards is 1224. If the smaller of the numbers on the removed cards is k, then k-20 =             .
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JEE Main/Advance
IMPORTANT
Let a, b, c be positive integers such that ba is an integer. If a, b,c are in geometric progression and the arithmetic mean of a, b, c  is b+2, then value of a2+a-14a+1 is
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JEE Main/Advance
IMPORTANT
Suppose that all the terms of an arithmetic progression (A.P.) are natural numbers. If the ratio of the sum of the first seven terms to the sum of the first eleven terms is 6:11 and the seventh term lies in between 130 and 140, then the common difference of this A.P. is
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JEE Main/Advance
IMPORTANT
The sides of a right angled triangle are in arithematic progression (A.P). If the triangle has area 24, Then what is the length of its smallest side?
HARD
JEE Main/Advance
IMPORTANT
Let X be the set consisting of the first 2018 terms of the arithmetic progression 1,6,11,..., and Y be the set consisting of the first 2018 terms of the arithmetic progression 9,16,23,...., Then , the number of elements in the set XY is             .