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Sequences and Series question

2018 · 16 Apr · Shift 1 · Q31

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PYQ Library
JEE Main
Mathematics
Sequences and Series
2018 · 16 Apr · Shift 1 · Q31

Sequences and Series question

2018 · 16 Apr · Shift 1 · Q31

JEE MainMathematicsSequences and SeriesMCQ+4 / −1

Let

{1 \over {{x_1}}},{1 \over {{x_2}}},...,{1 \over {{x_n}}}\,\,

(xi

e

0 for i = 1, 2, ..., n) be in A.P. such that x1=4 and x21 = 20. If n is the least positive integer for which

{x_n} \gt 50,

then

\sum\limits_{i = 1}^n {\left( {{1 \over {{x_i}}}} \right)}

is equal to :

A
${1 \over 8}$
B
3
C
${{13} \over 8}$
D
${{13} \over 4}$

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