MATHEMATICS for CLASS XI>Chapter 21 - Some Special Series>VERY SHORT ANSWER QUESTIONS (VSAQs)>Q 6

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IMPORTANT

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Write the sum of $20$ terms of the series: $1 + \frac{1}{2} (1 + 2) + \frac{1}{3} (1 + 2 + 3) + \dots$

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Important Questions on Some Special Series

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11th CBSE

IMPORTANT

MATHEMATICS for CLASS XI>Chapter 21 - Some Special Series>VERY SHORT ANSWER QUESTIONS (VSAQs)>Q 7

Write the

50^{t h}

term of the series

2 + 3 + 6 + 11 + 18 + \dots

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IMPORTANT

MATHEMATICS for CLASS XI>Chapter 21 - Some Special Series>VERY SHORT ANSWER QUESTIONS (VSAQs)>Q 8

Let

S_{n}

denote the sum of the cubes of first

n

natural numbers and

s_{n}

denote the sum of first

n

natural numbers. Then, write the value of

\sum_{r = 1}^{n} \frac{S_{r}}{s_{r}}

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IMPORTANT

MATHEMATICS for CLASS XI>Chapter 21 - Some Special Series>MULTIPLE CHOICE QUESTIONS (MCQs)>Q 1

The sum to

n

terms of the series

\frac{1}{\sqrt{1} + \sqrt{3}} + \frac{1}{\sqrt{3} + \sqrt{5}} + \frac{1}{\sqrt{5} + \sqrt{7}} + \dots \dots

is

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IMPORTANT

MATHEMATICS for CLASS XI>Chapter 21 - Some Special Series>MULTIPLE CHOICE QUESTIONS (MCQs)>Q 2

The sum of the series :

\frac{1}{\log_{2} 4} + \frac{1}{\log_{4} 4} + \frac{1}{\log_{8} 4} + \dots + \frac{1}{\log_{2^{n}} 4}

is

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11th CBSE

IMPORTANT

MATHEMATICS for CLASS XI>Chapter 21 - Some Special Series>MULTIPLE CHOICE QUESTIONS (MCQs)>Q 3

The value of

\sum_{r = 1}^{n} \{(2 r - 1) a + \frac{1}{b^{r}}\}

is equal to

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IMPORTANT

MATHEMATICS for CLASS XI>Chapter 21 - Some Special Series>MULTIPLE CHOICE QUESTIONS (MCQs)>Q 4

If

Σ n = 210,

then

Σ n^{2} =

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IMPORTANT

MATHEMATICS for CLASS XI>Chapter 21 - Some Special Series>MULTIPLE CHOICE QUESTIONS (MCQs)>Q 5

If

S_{n} = \sum_{r = 1}^{n} \frac{1 + 2 + 2^{2} + \dots Sum to r terms}{2^{r}},

then

S_{n}

is equal to

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11th CBSE

IMPORTANT

MATHEMATICS for CLASS XI>Chapter 21 - Some Special Series>MULTIPLE CHOICE QUESTIONS (MCQs)>Q 6

If

1 + \frac{1 + 2}{2} + \frac{1 + 2 + 3}{3} + \dots

to

n

terms is

S

. Then

S

is equal to