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Let a1, a2, a3,, a49 be in A.P. such thatk=012a4k+1=416 and a9+a43=66. If a12+a22++a172=140m, then m is equal to

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Important Questions on Sequences and Series

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IMPORTANT
If cos4θsec2α, 12 and sin4θcosec2α are in A.P., then cos8θsec6α, 12 and sin8θcosec6α are in
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IMPORTANT
An A.P. consist of even number of terms 2n having middle terms equal to 1 and 7, respectively. If n is the maximum value which satisfy t1t2n+7130, then the value of the first term of the series is
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IMPORTANT
For a, b & cR-{0}, let a+b1-ab, b, b+c1-bc are in A.P., if α and β are the roots of the quadratic equation 2acx2+2abcx+(a+c)=0, then the value of (1+α)(1+β) is
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IMPORTANT
In the sixth, seventh, eighth, and ninth basketball games of the season, a player scored 23, 14, 11, and 20 points, respectively. Her points per-game average was higher after nine games than it was after the first five games. Her average after ten games was greater than 18. What is the least number of points she could have scored in the tenth game?
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A large equilateral triangle is constructed by using toothpicks to create rows of small equilateral triangles. For example, in the figure we have 3 rows of small congruent equilateral triangles, with 5 small triangles in the base row. Total N number of toothpicks would be needed to construct a large equilateral triangle if the base row of the triangle consists of 2003 small equilateral triangles. Then find the sum of all digits of N.

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ABC is a right-angled triangle in which B=90° and BC=a. If n points L1, L2, , Ln on AB is divided in n+1 equal parts and L1M1, L2M2, LnMn are line segments parallel to BC and M1, M2, .Mn are on AC, then the sum of the lengths of L1M1, L2M2, ..LnMn is
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IMPORTANT
If tan2π18, x and tan7π18 are in A.P. and tan2π18, y and tan5π18 are in A.P., then the value of xy will be
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JEE Main
IMPORTANT
Given the sequence of numbers x1,x2,x3,x4,, x2005 which satisfy x1x1+1=x2x2+3=x3x3+5==x2005x2005+4009, the nature of the sequence is