Quantrex Academy Quantrex AcademyPYQs with solutions · JEE · NEET · NDA

Home · NDA PYQs · Mathematics · Sequences and Series

NDA Sequences and Series PYQs with Solutions

182 previous year questions from Sequences and Series (NDA Mathematics) with answers and solutions. Numbered list, year tags, and one-tap solutions — built for serious JEE / NEET practice.

182 questionsMathematics2010–2026Answers + solutions

About Sequences and Series PYQs

Sequences and Series has 182 previous year questions in the Quantrex Academy NDA Mathematics bank. The 182 questions in this list come from NDA (182), spanning 2010 to 2026. Each question opens on its own page with the options, the correct answer and the worked solution where available.

Questions by year (this list)

  • 2026: 5
  • 2025: 10
  • 2024: 13
  • 2023: 15
  • 2022: 15
  • 2021: 15
  • 2020: 1
  • 2019: 13
  • 2018: 12
  • 2017: 13
  • 2016: 12
  • 2015: 7

Sequences and Series questions with solutions

1

Let p , q and r be three unequal numbers such that p , q and r are in AP. If (q-p) , (r-q) and p are in GP, then (p+q):(q+r):(r+p) equals

NDA 2026 Solution View → 2

If p^ th term of an AP is k , then what is the sum of p^ th term, (p+q)^ th term and (p-q)^ th term of the AP ?

NDA 2026 Solution View → 3

If p , g_1 , g_2 and q are in GP and m is the arithmetic mean of p and q , then (g_1^2)/(g_2)+(g_2^2)/(g_1) is equal to

NDA 2026 Solution View → 4

The sum of the first n terms of an AP is 3n^2+5n . If the m^ th term of the AP is 68 , then what is the value of m ?

NDA 2026 Solution View → 5

Passage: Let X(a,p) , Y(b,q) and Z(c,r) be the points such that a , b and c are in AP. Question: If p , q and r are not in AP and b=c , then the line joining the points X , Y and

NDA 2026 Solution View → 6

If (10 + _ 10 x) , (10 + _ 10 y) and (10 + _ 10 z) are in AP, then consider the following statements: I. The GM of x and z is y^2 . II. The AM of _ 10 x and _ 10 z is _ 10 y .

NDA 2025 Solution View → 7

How many terms of the series 1 + 3 + 5 + 7 + … amount to a sum equal to 12345678987654321 ?

NDA 2025 Solution View → 8

For the following two (02) items: Let (6 + 10 + 14 + … up to m terms) = (1 + 3 + 5 + 7 + … up to n terms) , where m How many values of m are possible?

NDA 2025 Solution View → 9

For the following two (02) items: Let (6 + 10 + 14 + … up to m terms) = (1 + 3 + 5 + 7 + … up to n terms) , where m What is the relation between m and n ?

NDA 2025 Solution View → 10

How many terms are identical in the two APs 19, 21, 23, … up to 110 terms and 19, 22, 25, 28, … up to 75 terms?

NDA 2025 Solution View → 11

If p , 1 , q are in AP and p , 2 , q are in GP, then which of the following statements is/are correct? I. p , 4 , q are in HP. II. (1)/(p) , (1)/(4) , (1)/(q) are in AP. Select

NDA 2025 Solution View → 12

The sum of the first 8 terms of a GP is five times the sum of its first 4 terms. If r ≠ 1 is the common ratio, then what is the number of possible real values of r ?

NDA 2025 Solution View → 13

If 5th, 7th and 13th terms of an AP are in GP, then what is the ratio of its first term to its common difference?

NDA 2025 Solution View → 14

The sum of the first k terms of a series S is 3k^2 + 5k . Which one of the following is correct?

NDA 2025 Solution View → 15

What is the harmonic mean of the numbers C(10,3) , C(10,4) , C(10,5) , C(10,6) and C(10,7) ?

NDA 2025 Solution View → 16

If p times the p^ th term of an AP is equal to q times the q^ th term (p ≠ q) , then what is the (p+q)^ th term equal to?

NDA 2024 Solution View → 17

Let p=In(x), q= (x³) and r= (x^5) , where x > 1 . Which of the following statements is/are correct? A. p, q and r are in AP. B. p, q and r can never be in GP. Select the answer

NDA 2024 Solution View → 18

Paragraph: The product of 5 consecutive terms of an AP is 229635. The first, second and fifth terms are in GP. Question: What is the sum of all five terms?

NDA 2024 Solution View → 19

If a, b, c are in AP ; b, c, d are in GP ; c, d , e are in HP, then which of the following is/are correct? 1. a, c and e are in GP 2. (1)/(a), (1)/(c), (1)/(e) are in GP Select

NDA 2024 Solution View → 20

An edible oil is sold at the rates 150,200,250,300 rupees per litre in four consecutive years. Assuming that an equal amount of money is spent on oil by a family in every year

NDA 2024 Solution View → 21

Let m=77^n . The index n is given a positive integral value at random. What is the probability that the value of m will have 1 in the units place?

NDA 2024 Solution View → 22

x_i 1 2 3 … n f_i 1 2^ -1 2^ -2 … 2^ -(n-1) What is ∑_i^n x_i f_i equal to?

NDA 2024 Solution View → 23

Paragraph: The product of 5 consecutive terms of an AP is 229635. The first, second and fifth terms are in GP. Question: What is the common difference?

NDA 2024 Solution View → 24

If the sum of the first n terms of a series is n(2 n+1) , then what is the n th term?

NDA 2024 Solution View → 25

Let x > 1, y > 1, z > 1 be in GP. Then (1)/(1+ x), (1)/(1+ y), (1)/(1+ z) are

NDA 2024 Solution View → 26

The mean of n observations 1,4,9,16, …, n^2 is 130. What is the value of n ?

NDA 2024 Solution View → 27

If a, b, c are in HP, then what is (1)/(b-a)+(1)/(b-c) equal to? 1. (2)/(b) 2. (1)/(a)+(1)/(c) 3. (1)/(2) ((1)/(a)+(1)/(b)+(1)/(c)) Select the correct answer using the code given

NDA 2024 Solution View → 28

In an A P , the ratio of the sum of the first p terms to the sum of the first q terms is p^2: q^2 . Which one of the following is correct?

NDA 2024 Solution View → 29

If the n^ th term of a sequence is (2 n+5)/(7) , then what is the sum of its first 140 terms?

NDA 2023 Solution View → 30

Let a_1, a_2, a_3 … be in AP such that a_1+a_5+a_ 10 +a_ 15 +a_ 20 +a_ 25 +a_ 30 +a_ 34 =300 What is a_1+a_5-a_ 10 -a_ 15 -a_ 20 -a_ 25 +a_ 30 +a_ 34 equal to?

NDA 2023 Solution View → 31

Let t_1, t_2, t_3, … be in GP. What is (t_1 t_3 … t_ 21 )^ (1)/(11) equal to?

NDA 2023 Solution View → 32

Let a_1, a_2, a_3 … be in AP such that a_1+a_5+a_ 10 +a_ 15 +a_ 20 +a_ 25 +a_ 30 +a_ 34 =300 What is ∑_ n=1 ^ 34 a_n equal to?

NDA 2023 Solution View → 33

What is the mean of the numbers 1,2,3, …, 10 with frequencies ^9 c_0, ^9 c_1, ^9 c_2, …, ^9 c_9 , respectively?

NDA 2023 Solution View → 34

If 2^ (1)/(c) , 2^ (b)/(a c) , 2^ (1)/(a) are in GP, then which one of the following is correct?

NDA 2023 Solution View → 35

In an AP, the first term is x and the sum of the first n terms is zero. What is the sum of next m terms?

NDA 2023 Solution View → 36

p, q, r and s are in AP such that p+s=8 and qr=15 . What is the difference between largest and smallest numbers?

NDA 2023 Solution View → 37

The first and the second terms of an AP are (5)/(2) and (23)/(12) respectively. If n^ th terms is the largest negative term, what is the value of n ?

NDA 2023 Solution View → 38

Paragraph: Consider the sum S=0!+1!+2!+3!+4!+…+100! Question: If the sum S is divided by 60 , what is the remainder?

NDA 2023 Solution View → 39

Paragraph: Given that m(θ)= ^2 θ+n^2 ^2 θ+2 n , where n is a fixed positive real number. Question: What is the least value of m(θ) ?

NDA 2023 Solution View → 40

If G is the geometric mean of numbers 1,2,2^2, 2^3, …, 2 n^ -1 , then what is the value of 1+2 _2 G ?

NDA 2023 Solution View → 41

If H is the harmonic mean of numbers 1,2.2^2, 2^3, … , 2 n^ -1 , then what is n / H equal to?

NDA 2023 Solution View → 42

If (a+b), 2 b,(b+c) are in HP, then which one of the following is correct?

NDA 2023 Solution View → 43

If H is the Harmonic Mean of three numbers ^ 10 C_4, ^ 10 C_5 , and ^ 10 C_6 , then what is the value of (270)/(H) ?

NDA 2023 Solution View → 44

Paragraph: Let P be the sum of first n positive terms of an increasing arithmetic progression A . Let Q be the sum of first n positive terms of another increasing arithmetic

NDA 2022 Solution View → 45

Paragraph: Let P be the sum of first n positive terms of an increasing arithmetic progression A . Let Q be the sum of first n positive terms of another increasing arithmetic

NDA 2022 Solution View → 46

Paragraph: Let f(x) be a function satisfying f(x+y)=f(x) f(y) for all x, y∈ ℕ such that f(1)=2 : Question: If ∑_ x=2 ^n f(x)=2044 , then what is the value of n ?

NDA 2022 Solution View → 47

Paragraph: Let f(x) be a function satisfying f(x+y)=f(x) f(y) for all x, y∈ ℕ such that f(1)=2 : Question: What is ∑_ x=1 ^6 2^x f(x) equal to?

NDA 2022 Solution View → 48

Paragraph: Let P be the sum of first n positive terms of an increasing arithmetic progression A . Let Q be the sum of first n positive terms of another increasing arithmetic

NDA 2022 Solution View → 49

Let x be the mean of squares of first n natural numbers and y be the square of mean of first n natural numbers. If (x)/(y)=(55)/(42) , then what is the value of n ?

NDA 2022 Solution View → 50

If (a+b)/(2) , b, (b+c)/(2) are in HP, then which one of the following is correct?

NDA 2022 Solution View → 51

If the sum of the first 9 terms of an AP is equal to sum of the first 11 terms, then what is the sum of the first 20 terms?

NDA 2022 Solution View → 52

The marks obtained by 51 students in a class are in AP with its first term 4 and common difference 3. What is the median of the marks?

NDA 2022 Solution View → 53

The marks obtained by 51 students in a class are in AP with its first term 4 and common difference 3. What is the mean of the marks?

NDA 2022 Solution View → 54

If the 5th term of an AP is (1)/(10) and its 10 th term is (1)/(5) , then what is the sum of first 50 terms?

NDA 2022 Solution View → 55

What is the arithmetic mean of 50 terms of an AP with first term 4 and common difference 4 ?

NDA 2022 Solution View → 56

The marks obtained by 51 students in a class are in AP with its first term 4 and common difference 3. What is the sum of the deviations measured from the median?

NDA 2022 Solution View → 57

If a, b, c are in GP where a > 0, b > 0, c > 0 , then which of the following are correct? 1. a^2, b^2, c^2 are in GP 2. (1)/(a), (1)/(b), (1)/(c) are in GP 3. a , b , c are in GP

NDA 2022 Solution View → 58

What is the value of aligned & 2(2 × 1)+3(3 × 2 × 1)+4(4 × 3 × 2 × 1)+ & 5(5 × 4 × 3 × 2 × 1)+… … … … … …+ & 9(9 × 8 × 7 × 6 × 5 × 4 × 3 × 2 × 1)+2 ? aligned

NDA 2022 Solution View → 59

Let p, q and 3 be respectively the first, third and fifth terms of an A.P. Let d be the common difference. If the product (p q) is minimum, then what is the value of d ?

NDA 2021 Solution View → 60

If a_n=n(n!) , then what is a_1+a_2+a_3+…+a_ 10 equal to?

NDA 2021 Solution View → 61

If g is the geometric mean of 2,4,8,16,32,64,128,256,512 , 1024, then which one of the following is correct?

NDA 2021 Solution View → 62

If the harmonic mean of 60 and x is 48 , then what is the value of x ?

NDA 2021 Solution View → 63

If the first term of an AP is 2 and the sum of the first five terms is equal to one-fourth of the sum of the next five terms, then what is the sum of the first ten terms?

NDA 2021 Solution View → 64

Consider the following statements : 1. If each term of a GP is multiplied by same non-zero number, then the resulting sequence is also a GP. 2. If each term of a GP is divided by

NDA 2021 Solution View → 65

If x^2, x,-8 are in AP, then which one of the following is correct?

NDA 2021 Solution View → 66

The third term of a GP is 3. What is the product of its first five terms?

NDA 2021 Solution View → 67

Let x be the HM and y be the GM of two positive numbers m and n . If 5 x=4 y , then which one of the following is correct?

NDA 2021 Solution View → 68

The geometric mean of a set of observations is computed as 10. The geometric mean obtained when each observation x_i is replaced by 3 x_i^4 is

NDA 2021 Solution View → 69

Let S_k denote the sum of first k terms of an AP. What is S_ 30 S_ 20 -S_ 10 equal to?

NDA 2021 Solution View → 70

If p=(1111 … up to n digits ) , then what is the value of 9 p^2+p ?

NDA 2021 Solution View → 71

If x, y, z are in GP, then which of the following is/are correct? 1. (3 x), (3 y), (3 z) are in AP 2. x y z+ (), x y z+ (y), x y z+ (z) are in HP Select the correct answer using

NDA 2021 Solution View → 72

If (1)/(b+c), (1)/(c+a), (1)/(a+b) are in HP, then Which of the following is/are correct? 1. a, b, c are in AP 2. (b+c)^2,(c+a)^2,(a+b)^2 are in GP Select the correct answer using

NDA 2021 Solution View → 73

What is the mean of natural numbers contained in the interval [15,64] ?

NDA 2021 Solution View → 74

If p^2, q^2 and r^2 (where .p, q, r 0) are in GP, then which of the following is/are correct? 1. p, q and r are in GP. 2. p, q and r are in AP . Select the correct answer using

NDA 2020 Solution View → 75

What is the value of 1-2+3-4+5-…+101 ?

NDA 2019 Solution View → 76

If the sum of first n terms of a series is (n+12) , then what is its third term?

NDA 2019 Solution View → 77

A geometric progression (GP) consists of 200 terms. If the sum of odd terms of the GP is m , and the sum of even terms of the GP is n , then what is its common ratio?

NDA 2019 Solution View → 78

Let m and n(m < n) be the roots of the equation x^2-16 x+39=0 . If four terms p, q, r and s are inserted between m and n to form an AP , then what is the value of p+q+r+s ?

NDA 2019 Solution View → 79

What is the value of 2+(1)/(2+(1)/(2+(1)/(2+… ∞)))

NDA 2019 Solution View → 80

Let a, b, c be in AP and k ≠ 0 be a real number. Which of the following are correct? 1. k a, k b, k c are in AP 2. k-a, k-b, k-c are in AP 3. (a)/(k), (b)/(k), (c)/(k) are in AP

NDA 2019 Solution View → 81

Let S_n be the sum of the first n terms of an AP. If S_ 2 n =3 n+14 n^2 , then what is the common difference?

NDA 2019 Solution View → 82

If 3rd, 8th and 13th terms of a GP are p, q and r respectively, then which one of the following is correct?

NDA 2019 Solution View → 83

A car travels first 60 km at a speed of 3 v km / hr and travels next 60 km at 2 v km / hr . What is the average speed of the car?

NDA 2019 Solution View → 84

The numbers 1,5 and 25 can be three terms (not necessarily consecutive) of

NDA 2019 Solution View → 85

What is the n^ th term of the sequence 25,-125,625 , -3125, … ?

NDA 2019 Solution View → 86

What is the Fourth term of an AP of n terms whose sum is n(n+1) ?

NDA 2019 Solution View → 87

The sum of (p+q)^ th and (p-q)^ th terms of an AP is equal to

NDA 2019 Solution View → 88

If an infinite GP has the first term x and the sum 5 , then which of the following is correct?

NDA 2018 Solution View → 89

The sum of the series 3-1+(1)/(3)-(1)/(9)+… . is equal to

NDA 2018 Solution View → 90

If u , vand w (all positive) are the p^ th , q^ th and r^ th terms of a GP, the determinant of the matrix | array lll In u & p & 1 In v & q & 1 In w & r & 1 array | is

NDA 2018 Solution View → 91

If x_ i > 0, y_ i > 0(i=1,2,3 n) are the values of two variable X and Y with geometric mean P and Q respectively, then the geometric mean of (X)/(Y) is

NDA 2018 Solution View → 92

Let T_r be the r^ th term of an AP for r=1,2,3, … If for some distinct positive integers m and n we have T_ m =1 / n and T_ n =1 / m , then what is T_ mn equal to?

NDA 2018 Solution View → 93

If the ratio of A M to G M of two positive numbers a and b is 5: 3 , then a: b is equal to

NDA 2018 Solution View → 94

What is the sum of all two-digit numbers which when divided by 3 leave 2 as the remainder?

NDA 2018 Solution View → 95

If x, (3)/(2), z are in AP; x, 3, z are in GP; then which one of the following will be in HP?

NDA 2018 Solution View → 96

If the second term of a GP is 2 and the sum of its infinite term is 8 , then the GP is

NDA 2018 Solution View → 97

If a, b, c are in AP or GP HP, then (a-b)/(b-c) is equal to

NDA 2018 Solution View → 98

The third term of a GP is 3. What is the product of the first five terms?

NDA 2018 Solution View → 99

If x=1-y+y^2-y^3+… . up to infinite terms, where |y| < 1 then which one of the following is correct?

NDA 2018 Solution View → 100

If S_ n =nP+ n(n-1) Q 2 , where S_ n denotes the sum of the first n terms of an AP , then the common difference is

NDA 2017 Solution View → 101

The value of the product 6^ (1)/(2) × 6^ (1)/(4) × 6^ (1)/(8) × 6^ (1)/(16) × … . up to infinite terms is

NDA 2017 Solution View → 102

If y=x+x^2+x^3+… up to infinite terms where x < 1 , then which one of the following is correct?

NDA 2017 Solution View → 103

A person is to count 4500 notes. Let a_n denote the number of notes he counts in the nth minute. If a_1=a_2=a_3=… . =a_ 10 =150 , and a_ 10 , a_ 11 , a_ 12 , … . are in AP with

NDA 2017 Solution View → 104

The value of (1)/( _3 e)+(1)/( _3 e^2)+(1)/( _3 e^4)+ … . up to infinite terms is

NDA 2017 Solution View → 105

If 1.3+2.3^2+3.3^3+… .+n .3^n= (2 n-1) 3^ a +b 3 then a and b are respectively

NDA 2017 Solution View → 106

What is the sum of the series 0.3+0.33+0.333+…. n terms?

NDA 2017 Solution View → 107

If the sum of m terms of an AP is n and the sum of n terms is m , then the sum of (m+n) terms is

NDA 2017 Solution View → 108

The fifth term of an AP of n terms, whose sum is n^2-2 n , is

NDA 2017 Solution View → 109

The sum of the first n terms of the series (1)/(2)+(3)/(4)+(7)/(8)+(15)/(16)+… . is equal to

NDA 2017 Solution View → 110

Let f(n)= [(1)/(4)+ n 1000 ], where [ x] denote the integral part of x . Then the value of ∑_ n=1 ^ 1000 f(n) is

NDA 2017 Solution View → 111

If x_1 and x_2 are positive quantities, then the condition for the difference between the arithmetic mean and the geometric mean to be greater than 1 is

NDA 2017 Solution View → 112

The sum of all the two-digit odd numbers is

NDA 2017 Solution View → 113

How many geometric progressions is/are possible containing 27,8 and 12 as three of its/their terms?

NDA 2016 Solution View → 114

Paragraph: Let a, x, y, z, b be in AP , where x+y+z=15 . Let a, p, q, r, b be in HP , where ^ -1 + ^ -1 + ^ -1 =(5)/(3) Question: What is the value of x y z ?

NDA 2016 Solution View → 115

Paragraph: Let a, x, y, z, b be in AP , where x+y+z=15 . Let a, p, q, r, b be in HP , where ^ -1 + ^ -1 + ^ -1 =(5)/(3) Question: What is the value of a b ?

NDA 2016 Solution View → 116

Paragraph: Let a, x, y, z, b be in AP , where x+y+z=15 . Let a, p, q, r, b be in HP , where ^ -1 + ^ -1 + ^ -1 =(5)/(3) Question: What is the value of pqr?

NDA 2016 Solution View → 117

Paragraph: The sixth term of an AP is 2 and its common difference is greater than 1. Question: What is the common difference of the AP so that the product of the first, fourth and

NDA 2016 Solution View → 118

Paragraph: The sixth term of an AP is 2 and its common difference is greater than 1. Question: What is the first term of the AP so that the product of the first, fourth and fifth

NDA 2016 Solution View → 119

Paragraph: The interior angles of a polygon of n sides are in AP. The smallest angle is 120^ ^ ∘ and the common difference is 5^ ^ ∘ . Question: How many possible values can n

NDA 2016 Solution View → 120

What is the greatest value of the positive integer n satisfying the condition 1+(1)/(2)+(1)/(4)+(1)/(8)+…..+ 1 2^ n-1 < 2-(1)/(1000) ?

NDA 2016 Solution View → 121

Paragraph: The interior angles of a polygon of n sides are in AP. The smallest angle is 120^ ^ ∘ and the common difference is 5^ ^ ∘ . Question: What is the largest interior angle

NDA 2016 Solution View → 122

Given that _x y, _z x, _y z are in GP, x y z=64 and x^3 , y^3, z^3 are in A.P. Which one of the following is correct? x y, y z and z x are

NDA 2016 Solution View → 123

If m is the geometric mean of ( y z )^ (yz) ,( z x )^ (zx) and ( x y )^ (xy) then what is the value of m ?

NDA 2016 Solution View → 124

Given that _x y, _z x, _y z are in GP, x y z=64 and x^3 , y^3, z^3 are in A.P. Which one of the following is correct? x, y and z are

NDA 2016 Solution View → 125

The value of the infinite product 6^ (1)/(2) × 6^ (1)/(2) × 6^ (3)/(8) × 6^ (1)/(4) × … is

NDA 2015 Solution View → 126

The n th term of an AP. is (3+n)/(4) , then the sum of first 105 terms is

NDA 2015 Solution View → 127

What is the sum of n terms of the series 2 + 8 + 18 + 32 +…. ?

NDA 2015 Solution View → 128

The arithmetic mean of 1,8,27,64, … . up to n terms is given by

NDA 2015 Solution View → 129

What is the sum of the series 0.5+0.55+0.555+… to n terms?

NDA 2015 Solution View → 130

If p, q, r are in one geometric progression and a, b, c are in another geometric progression, then ap, bq, cr are in

NDA 2015 Solution View → 131

If _ 10 2, _ 10 (2^x-1) and _ 10 (2^x+3) are three consecutive terms of an A.P, then the value of x is

NDA 2015 Solution View → 132

What is _ n arrow ∞ (1+2+3+…+n)/(1^2+2^2+3^2+… n^2) equal to?

NDA 2014 Solution View → 133

Let S_n denote the sum of first n terms of an AP and 3 S_n=S_ 2 n . What is S_ 3 n : S_n equal to?

NDA 2014 Solution View → 134

Let S_n denote the sum of first n terms of an AP and 3 S_n=S_ 2 n . What is S_ 3 n : S_ 2 n equal to ?

NDA 2014 Solution View → 135

The sum of an infinite GP is x and the common ratio r is such that |r| < 1 . If the first term of the GP is 2 , then which one of the following is correct?

NDA 2014 Solution View → 136

The sum of the series formed by the sequence 3 , 3 , 1, … upto infinity is:

NDA 2014 Solution View → 137

What is the mean of the squares of the first 20 natural numbers?

NDA 2014 Solution View → 138

What is the seventh term of the sequence 0,3,8,15 , 24, ….. ?

NDA 2013 Solution View → 139

The sum of the first five terms and the sum of the first ten terms of an AP are same. Which one of the following is the correct statement?

NDA 2013 Solution View → 140

If the positive integers a, b, c, d are in AP, then the numbers a b c, a b d, a c d, b c d are in

NDA 2013 Solution View → 141

The harmonic mean H of two numbers is 4 and the arithmetic mean A and geometric mean G satisfy the equation 2 A+G^2=27 . The two numbers are

NDA 2013 Solution View → 142

If the numbers n-3,4 n-2,5 n+1 are in AP , what is the value of n ?

NDA 2013 Solution View → 143

The arithmetic mean of the squares of the first n natural numbers is

NDA 2013 Solution View → 144

What is 0.9+0.09+0.009+… equal to?

NDA 2013 Solution View → 145

Consider the following statements : 1. The sum of cubes of first 20 natural numbers is 44400. 2. The sum of squares of first 20 natural numbers is 2870. Which of the above

NDA 2012 Solution View → 146

The sum of first 10 terms and 20 terms of an AP are 120 and 440 respectively. What is the common difference?

NDA 2012 Solution View → 147

The sum of first 10 terms and 20 terms of an AP are 120 and 440 respectively. What is its first term?

NDA 2012 Solution View → 148

What is the sum of first eight terms of the series 1-(1)/(2)+(1)/(4)-(1)/(8)+… … ?

NDA 2012 Solution View → 149

What is the mean of first n odd natural numbers?

NDA 2012 Solution View → 150

What is the arithmetic mean of first 16 natural numbers with weights being the number itself?

NDA 2012 Solution View → 151

What is the n^ th term of the sequence 1,5,9,13 , 17, … ?

NDA 2012 Solution View → 152

The geometric mean and harmonic mean of two nonnegative observations are 10 and 8 respectively. Then what is the arithmetic mean of the observations equal to?

NDA 2012 Solution View → 153

If p, q, r are in AP as well as GP, then which one of the following is correct?

NDA 2012 Solution View → 154

What is the sum of the series 1-(1)/(2)+(1)/(4)-(1)/(8)+… equal to?

NDA 2012 Solution View → 155

If the sequence \ s_n\ is a geometric progression and s_2s_ 11 =s_p ~s_8 , then what is the value of p ?

NDA 2012 Solution View → 156

What is the geometric mean of the sequence 1,2,4,8 ,.........., 2^n ?

NDA 2012 Solution View → 157

What does the series 1+3^ -(1)/(2) +3+ 1 3 3 +… represent?

NDA 2012 Solution View → 158

If 1 / 4,1 / x, 1 / 10 are in HP, then what is the value of x ?

NDA 2012 Solution View → 159

What is the 10^ th common term between the series 2+6+10+… and 1+6+11+… ?

NDA 2011 Solution View → 160

If the 10^ th term of a GP is 9 and 4^ th term is 4 , then what is its 7^ th term?

NDA 2011 Solution View → 161

If n!, 3 ×(n!) and (n+1)! Are in GP, then the value of n will be

NDA 2011 Solution View → 162

If _ 10 2, _ 10 (2^x-1), _ 10 (2^x+3) are three consecutive terms of an AP, then which one of the following is correct?

NDA 2011 Solution View → 163

If a, b, c, d, e, f are in AP , then (e-c) is equal to which one of the following?

NDA 2011 Solution View → 164

What is the geometric mean of 10,40 and 20 ?

NDA 2011 Solution View → 165

What is the value of 8+2 8+2 8+2 8+… ∞ ?

NDA 2011 Solution View → 166

If the arithmetic and geometric means of two numbers are 10,8 respectively, then one number exceeds the other number by

NDA 2011 Solution View → 167

In a GP of positive terms, any term is equal to one-third of the sum of next two terms. What is the common ratio of the GP?

NDA 2011 Solution View → 168

If (1)/(b-a)+(1)/(b-c)=(1)/(a)+(1)/(c) then a, b, c are in

NDA 2011 Solution View → 169

The average daily income of workers of a factory including that of the owner is ₹ 110. However, if the income of the owner is excluded, the average daily income of the remaining 9

NDA 2011 Solution View → 170

Which term of the series (1)/(4),-(1)/(2), 1, … is -128 ?

NDA 2011 Solution View → 171

What is the sum of 3 + 1 3 + 1 3 3 +… ?

NDA 2011 Solution View → 172

What is the geometric mean of the data 2,4,8,16,32 ?

NDA 2011 Solution View → 173

If the AM and GM between two numbers are in the ratio m: n , then what is the ratio between the two numbers?

NDA 2010 Solution View → 174

A square is drawn by joining mid-point of the sides of a square. Another square is drawn inside the second square in the same way and the process is continued indefinitely. If the

NDA 2010 Solution View → 175

The arithmetic mean of two numbers exceeds their geometric mean by 2 and the geometric mean exceeds their harmonic mean by 1.6. What are the two numbers?

NDA 2010 Solution View → 176

The geometric mean of three numbers was computed as 6. It was subsequently found that, in this computation, a number 8 was wrongly read as 12. What is the correct geometric mean?

NDA 2010 Solution View → 177

If the AM and HM of two numbers are 27 and 12 respectively, then what is their GM equal to?

NDA 2010 Solution View → 178

The 59th term of an AP is 449 and the 449th term is 59. Which term is equal to 0 (zero)?

NDA 2010 Solution View → 179

If p times the p th term of an AP is q times the q th term, then what is the (p+q) th term equal to?

NDA 2010 Solution View → 180

What is the sum of all natural numbers between 200 and 400 which are divisible by 7 ?

NDA 2010 Solution View → 181

Let a, b, c be in AP. Consider the following statements: I. (1)/(a b), (1)/(c a), (1)/(b c) are in AP. II. 1 b + c , 1 c + a , 1 a + b are in AP. Which of the statements given

NDA 2010 Solution View → 182

The sum of an infinite geometric progression is 6. If the sum of the first two terms is 9 / 2 , then what is the first term?

NDA 2010 Solution View →
Practice all Sequences and Series questions in the app →

Related NDA Mathematics chapters

Trigonometric Ratios & Identities (295)Statistics (236)Probability (201)Three Dimensional Geometry (176)Quadratic Equation (157)Matrices (153)Determinants (130)Functions (129)Permutation and Combination (129)Differential Equations (127)Definite Integration (110)Differentiation (104)

Sequences and Series in other exams

JEE Sequences and Series (748)BITSAT Sequences and Series (51)