Sequences and Series
462 Questions
Start JEE Mains Test
2007
Q401
JEE Advanced
MCQ
14 Mar 2026
The sum V$_1$ + V$_2$ + ... + V$_n$ is
A.
${1 \over {12}}n(n + 1)(3{n^2} - n + 1)$
B.
${1 \over {12}}n(n + 1)(3{n^2} + n + 2)$
C.
${1 \over 2}n(2{n^2} - n + 1)$
D.
${1 \over 3}(2{n^3} - 2n + 3)$
2007
Q402
JEE Advanced
MCQ
14 Mar 2026
T$_r$ is always
A.
an odd number
B.
an even number
C.
a prime number
D.
a composite number
2007
Q403
JEE Advanced
MCQ
14 Mar 2026
Which one of the following is a correct statement?
A.
Q$_1$, Q$_2$, Q$_3$, ... are in A.P. with common difference 5
B.
Q$_1$, Q$_2$, Q$_3$, ... are in A.P. with common difference 6
C.
Q$_1$, Q$_2$, Q$_3$, ... are in A.P. with common difference 11
D.
Q$_1$ = Q$_2$ = Q$_3$, ...
2006
Q404
JEE Mains
MCQ
14 Mar 2026
If ${{a_1},{a_2},....{a_n}}$ are in H.P., then the expression ${{a_1}\,{a_2} + \,{a_2}\,{a_3}\, + .... + {a_{n - 1}}\,{a_n}}$ is equal to
A.
$n({a_1}\, - {a_n})$
B.
$(n - 1)({a_1}\, - {a_n})$
C.
$n{a_1}{a_n}$
D.
$(n - 1)\,\,{a_1}{a_n}$
2006
Q405
JEE Mains
MCQ
14 Mar 2026
Let ${a_1}$, ${a_2}$, ${a_3}$.....be terms on A.P. If ${{{a_1} + {a_2} + .....{a_p}} \over {{a_1} + {a_2} + .....{a_q}}} = {{{p^2}} \over {{q^2}}},\,p \ne q,\,then\,{{{a_6}} \over {{a_{21}}}}\,$ equals
A.
${{41} \over {11}}$
B.
${7 \over 2}$
C.
${2 \over 7}$
D.
${{11} \over {41}}$
2005
Q406
JEE Mains
MCQ
14 Mar 2026
The sum of the series $1 + {1 \over {4.2!}} + {1 \over {16.4!}} + {1 \over {64.6!}} + .......$ ad inf. is
A.
${{e - 1} \over {\sqrt e }}\,$
B.
${{e + 1} \over {\sqrt e }}$
C.
${{e - 1} \over {2\sqrt e }}$
D.
${{e + 1} \over {2\sqrt e }}$
2005
Q407
JEE Mains
MCQ
14 Mar 2026
If $x = \sum\limits_{n = 0}^\infty {{a^n},\,\,y = \sum\limits_{n = 0}^\infty {{b^n},\,\,z = \sum\limits_{n = 0}^\infty {{c^n},} } } \,\,$ where a, b, c are in A.P and $\,\left| a \right| < 1,\,\left| b \right| < 1,\,\left| c \right| < 1$ then x, y, z are in
A.
G.P.
B.
A.P.
C.
Arithmetic-Geometric Progression
D.
H.P.
2005
Q408
JEE Advanced
MCQ
14 Mar 2026
In the quadratic equation $\,\,a{x^2} + bx + c = 0,$ $\Delta $ $ = {b^2} - 4ac$ and $\alpha + \beta ,\,{\alpha ^2} + {\beta ^2},\,{\alpha ^3} + {\beta ^3},$ are in G.P. where $\alpha ,\beta $ are the root of $\,\,a{x^2} + bx + c = 0,$ then
A.
$\Delta \ne 0$
B.
$b\Delta = 0$
C.
$c\Delta = 0$
D.
$\Delta = 0$
2005
Q409
JEE Advanced
MCQ
14 Mar 2026
If total number of runs scored in $n$ matches is $\left(\frac{n+1}{4}\right)\left(2^{n+1}-n-2\right)$ where $n > 1$, and the runs scored in the $k^{\text {th }}$ match are given by $k .2^{n+1-k}$, where $1 \leq k \leq n$. Find, $n$.
A.
5
B.
7
C.
15
D.
1
2004
Q410
JEE Mains
MCQ
14 Mar 2026
The sum of series ${1 \over {2\,!}} + {1 \over {4\,!}} + {1 \over {6\,!}} + ........$ is
A.
${{\left( {{e^2} - 2} \right)} \over e}\,$
B.
${{{{\left( {e - 1} \right)}^2}} \over {2e}}$
C.
${{\left( {{e^2} - 1} \right)} \over {2e}}\,$
D.
${{\left( {{e^2} - 1} \right)} \over 2}$
2004
Q411
JEE Mains
MCQ
14 Mar 2026
Let ${{T_r}}$ be the rth term of an A.P. whose first term is a and common difference is d. If for some positive integers m, n, $m \ne n,\,\,{T_m} = {1 \over n}\,\,and\,{T_n} = {1 \over m},\,$ then a - d equals
A.
${1 \over m} + {1 \over n}$
B.
1
C.
${1 \over {m\,n}}$
D.
0
2004
Q412
JEE Mains
MCQ
14 Mar 2026
The sum of the first n terms of the series ${1^2} + {2.2^2} + {3^2} + {2.4^2} + {5^2} + {2.6^2} + ....\,is\,{{n{{(n + 1)}^2}} \over 2}$ when n is even. When n is odd the sum is
A.
${\left[ {{{n(n + 1)} \over 2}} \right]^2}$
B.
${{{n^2}(n + 1)} \over 2}$
C.
${{n{{(n + 1)}^2}} \over 4}$
D.
$\,{{3n(n + 1)} \over 2}$
2004
Q413
JEE Advanced
MCQ
14 Mar 2026
An infinite G.P. has first term '$x$' and sum '$5$', then $x$ belongs to
A.
$x < - 10$
B.
$ - 10 < x < 0$
C.
$0 < x < 10$
D.
$x > 10$
2003
Q414
JEE Mains
MCQ
14 Mar 2026
The sum of the serier ${1 \over {1.2}} - {1 \over {2.3}} + {1 \over {3.4}}..............$ up to $\infty $ is equal to
A.
$\log {\,_e}\left( {{4 \over e}} \right)\,\,$
B.
$2\,\log {\,_e}2$
C.
$\log {\,_e}2 - 1\,$
D.
$\log {\,_e}2$
2003
Q415
JEE Advanced
Numerical
14 Mar 2026
If a, b, c are in A.P., ${a^2}$, ${b^2}$, ${c^2}$ are in H.P., then prove that either a = b = c or a, b, ${ - {c \over 2}}$ form a G.P.
Correct Answer: solve it
2002
Q416
JEE Mains
MCQ
14 Mar 2026
The value of $\,{2^{1/4}}.\,\,{4^{1/8}}.\,{8^{1/16}}...\infty $ is
A.
1
B.
2
C.
3/2
D.
4
2002
Q417
JEE Mains
MCQ
14 Mar 2026
${1^3} - \,\,{2^3} + {3^3} - {4^3} + ... + {9^3} = $
A.
425
B.
- 425
C.
475
D.
- 475
2002
Q418
JEE Mains
MCQ
14 Mar 2026
l, m, n are the ${p^{th}}$, ${q^{th}}$ and ${r^{th}}$ term of a G.P all positive, $then\,\left| {\matrix{
{\log \,l} & p & 1 \cr
{\log \,m} & q & 1 \cr
{\log \,n} & r & 1 \cr
} } \right|\,equals$
A.
- 1
B.
2
C.
1
D.
0
2002
Q419
JEE Mains
MCQ
14 Mar 2026
Sum of infinite number of terms of GP is 20 and sum of their square is 100. The common ratio of GP is
A.
5
B.
3/5
C.
8/5
D.
1/5
2002
Q420
JEE Mains
MCQ
14 Mar 2026
If 1, ${\log _9}\,\,({3^{1 - x}} + 2),\,\,{\log _3}\,\,({4.3^x} - 1)$ are in A.P. then x equals
A.
${\log _3}\,4\,\,\,$
B.
$1 - \,{\log _3}\,4\,$
C.
$1 - \,{\log _4}\,3$
D.
${\log _4}\,3$
2002
Q421
JEE Mains
MCQ
14 Mar 2026
Fifth term of a GP is 2, then the product of its 9 terms is
A.
256
B.
512
C.
1024
D.
none of these
2002
Q422
JEE Advanced
MCQ
14 Mar 2026
Suppose $a, b, c$ are in A.P. and ${a^2},{b^2},{c^2}$ are in G.P. If $a < b < c$ and $a + b + c = {3 \over 2},$ then the value of $a$ is
A.
${1 \over {2\sqrt 2 }}$
B.
${1 \over {2\sqrt 3 }}$
C.
${1 \over 2} - {1 \over {\sqrt 3 }}$
D.
${1 \over 2} - {1 \over {\sqrt 2 }}$
2002
Q423
JEE Advanced
Numerical
14 Mar 2026
Let a, b be positive real numbers. If a, ${{A_1},{A_2}}$, b are in arithmetic progression, a, ${{G_1},{G_2}}$, b are in geometric progression and a, ${{H_1},{H_2}}$, b are in harmonic progression, show that $\,{{{G_1},{G_2}} \over {{H_1},{H_2}}} = {{{A_1} + {A_2}} \over {{H_1} + {H_2}}} = {{(2a + b)\,(a + 2b)} \over {9ab}}$.
Correct Answer: solve it.
2001
Q424
JEE Advanced
MCQ
14 Mar 2026
Let the positive numbers $a,b,c,d$ be in A.P. Then $abc,$ $abd,$ $acd,$ $bcd,$ are
A.
NOT in A.P./GP./H.P.
B.
inA.P.
C.
in GP.
D.
in H.P.
2001
Q425
JEE Advanced
MCQ
14 Mar 2026
If the sum of the first $2n$ terms of the A.P.$2,5,8,......,$ is equal to the sum of the first $n$ terms of the A.P.$57,59,61,.....,$ then $n$ equals
A.
10
B.
12
C.
11
D.
13
2001
Q426
JEE Advanced
MCQ
14 Mar 2026
Let $\alpha $, $\beta $ be the roots of ${x^2} - x + p = 0$ and $\gamma ,\delta $ be the roots of ${x^2} - 4x + q = 0.$ If $\alpha ,\beta ,\gamma ,\delta $ are in G.P., then the integral values of $p$ and $q$ respectively, are
A.
$-2,-32$
B.
$-2,3$
C.
$-6,3$
D.
$-6,-32$
2001
Q427
JEE Advanced
Numerical
14 Mar 2026
Let ${a_1}$, ${a_2}$,.....,${a_n}$ be positive real numbers in geometric progression. For each n, let ${A_n}$, ${G_n}$, ${H_n}$ be respectively, the arithmetic mean , geometric mean, and harmonic mean of ${a_1}$,${a_2}$......,${a_n}$. Find an expression for the geometric mean of ${G_1}$,${G_2}$,.....,${G_n}$ in terms of ${A_1}$,${A_2}$,.....,${A_n}$,${H_n}$,${H_1}$,${H_2}$,........,${H_n}$.
Correct Answer: $$G = {\left( {{A_1},{A_2}....{A_n}\,{H_1},\,{H_2}.....{H_n}} \right)^{{\raise0.5ex\hbox{$\scriptstyle 1$}
\kern-0.1em/\kern-0.15em
\lower0.25ex\hbox{$\scriptstyle {2n}$}}}}$$
2000
Q428
JEE Advanced
MCQ
14 Mar 2026
Consider an infinite geometric series with first term a and common ratio $r$. If its sum is 4 and the second term is 3/4, then
A.
$a = {4 \over 7},r = {3 \over 7}\,\,\,\,$
B.
$a = 2,\,r = {3 \over 8}$
C.
$a = {3 \over 2},r = {1 \over 2}$
D.
$a = 3,\,r = {1 \over 4}$
2000
Q429
JEE Advanced
Numerical
14 Mar 2026
The fourth power of the common difference of an arithmatic progression with integer entries is added to the product of any four consecutive terms of it. Prove that the resulting sum is the square of an integer.
Correct Answer: solve it
1999
Q430
JEE Advanced
MCQ
14 Mar 2026
The harmonic mean of the roots of the equation $\left( {5 + \sqrt 2 } \right){x^2} - \left( {4 + \sqrt 5 } \right)x + 8 + 2\sqrt 5 = 0$ is
A.
2
B.
4
C.
6
D.
8
1999
Q431
JEE Advanced
MCQ
14 Mar 2026
Let ${a_1},{a_2},......{a_{10}}$ be in $A,\,P,$ and ${h_1},{h_2},......{h_{10}}$ be in H.P. If ${a_1} = {h_1} = 2$ and ${a_{10}} = {h_{10}} = 3,$ then ${a_4}{h_7}$ is
A.
2
B.
3
C.
5
D.
6
1999
Q432
JEE Advanced
MSQ
14 Mar 2026
For a positive integer $n$, let
$a\left( n \right) = 1 + {1 \over 2} + {1 \over 3} + {1 \over 4} + .....\,{1 \over {\left( {{2^n}} \right) - 1}}$. Then
$a\left( n \right) = 1 + {1 \over 2} + {1 \over 3} + {1 \over 4} + .....\,{1 \over {\left( {{2^n}} \right) - 1}}$. Then
A.
$a\left( {100} \right) \le 100$
B.
$a\left( {100} \right) > 100$
C.
$a\left( {200} \right) \le 100$
D.
$a\left( {200} \right) > 100$
1999
Q433
JEE Advanced
Numerical
14 Mar 2026
Let a, b, c, d be real numbers in G.P. If u, v, w, satisfy the system of equations
u + 2v + 3w = 6
4u + 5v + 6w = 12
6u + 9v = 4
u + 2v + 3w = 6
4u + 5v + 6w = 12
6u + 9v = 4
then show that the roots of the equation $\left( {{1 \over u} + {1 \over v} + {1 \over w}} \right){x^2}$
$ + [{(b - c)^2} + {(c - a)^2} + {(d - b)^2}]x + u + v + w = 0$ and $20{x^2} + 10{(a - d)^2}x - 9 = 0$ are reciprocals of each other.
Correct Answer: solve it
1998
Q434
JEE Advanced
MCQ
14 Mar 2026
Let $n$ be an odd integer. If $\sin n\theta = \sum\limits_{r = 0}^n {{b_r}{{\sin }^r}\theta ,} $ for every value of $\theta ,$ then
A.
${b_0} = 1,\,b = 3$
B.
${b_0} = 0,\,{b_1} = n$
C.
${b_0} = - 1,\,{b_1} = n$
D.
${b_0} = 0,\,{b_1} = {n^2} - 3n + 3$
1998
Q435
JEE Advanced
MCQ
14 Mar 2026
If $x > 1,y > 1,z > 1$ are in G.P., then ${1 \over {1 + In\,x}},{1 \over {1 + In\,y}},{1 \over {1 + In\,z}}$ are in
A.
A.P.
B.
H.P.
C.
G.P.
D.
None of these
1998
Q436
JEE Advanced
MCQ
14 Mar 2026
Let ${T_r}$ be the ${r^{th}}$ term of an A.P., for $r=1, 2, 3, ....$ If for some positive integers $m$, $n$ we have
${T_m} = {1 \over n}$ and ${T_n} = {1 \over m},$ then ${T_n} = {1 \over m},$ equals
${T_m} = {1 \over n}$ and ${T_n} = {1 \over m},$ then ${T_n} = {1 \over m},$ equals
A.
${1 \over {mn}}$
B.
${1 \over {mn}} + {1 \over n}$
C.
$1$
D.
$0$
1997
Q437
JEE Advanced
Numerical
14 Mar 2026
Let $p$ and $q$ be roots of the equation ${x^2} - 2x + A = 0$ and let $r$ and $s$ be the roots of the equation ${x^2} - 18x + B = 0.$ If $p < q < r < s$ are in arithmetic progression, then $A = \,..........$ and $B = \,..........$
Correct Answer: $$-3,77$$
1996
Q438
JEE Advanced
Numerical
14 Mar 2026
The real numbers ${x_1}$, ${x_2}$, ${x_3}$ satisfying the equation ${x^3} - {x^2} + \beta x + \gamma = 0$ are in AP. Find the intervals in which $\beta \,\,and\,\gamma $ lie.
Correct Answer: $$\beta \,\, \in \left( { - \infty ,\,{1 \over 3}} \right],\,\gamma \, \in \,\left[ { - {1 \over {27}},\infty } \right)$$
1996
Q439
JEE Advanced
Numerical
14 Mar 2026
For any odd integer $n$ $ \ge 1,\,\,{n^3} - {\left( {n - 1} \right)^3} + .... + {\left( { - 1} \right)^{n - 1}}\,{1^3} = ........$
Correct Answer: $${1 \over 4}{\left( {n + 1} \right)^2}\left( {2n - 1} \right)$$
1994
Q440
JEE Advanced
MCQ
14 Mar 2026
If $In\left( {a + c} \right),In\left( {a - c} \right),In\left( {a - 2b + c} \right)$ are in A.P., then
A.
$a,\,b,\,c$ are in A.P.
B.
${a^2},\,{b^2},\,{c^2}$ are in A.P.
C.
$a,\,b,\,c$ are in G.P.
D.
$a,\,b,\,c$ are in H.P.
1993
Q441
JEE Advanced
MSQ
14 Mar 2026
For $0 < \phi < \pi /2,$ if
$x = $$\sum\limits_{n = 0}^\infty {{{\cos }^{2n}}\phi ,y = \sum\limits_{n = 0}^\infty {{{\sin }^{2n}}\phi ,\,\,\,\,z = \sum\limits_{n = 0}^{} {{{\cos }^{2n}}\phi {{\sin }^{2n}}\phi } } } \infty $ then
$x = $$\sum\limits_{n = 0}^\infty {{{\cos }^{2n}}\phi ,y = \sum\limits_{n = 0}^\infty {{{\sin }^{2n}}\phi ,\,\,\,\,z = \sum\limits_{n = 0}^{} {{{\cos }^{2n}}\phi {{\sin }^{2n}}\phi } } } \infty $ then
A.
$xyz = xz + y$
B.
$xyz = xy + z$
C.
$xyz = x + y + z$
D.
$xyz = yz + x$
1992
Q442
JEE Advanced
Numerical
14 Mar 2026
Let the harmonic mean and geometric mean of two positive numbers be the ratio 4 : 5. Then the two number are in the ratio .........
Correct Answer: 4 : 1 or 1 : 4
1991
Q443
JEE Advanced
Numerical
14 Mar 2026
If ${S_1}$, ${S_2}$, ${S_3}$,.............,${S_n}$ are the sums of infinite geometric series whose first terms are 1, 2, 3, ...................,n and whose common ratios are ${1 \over 2}$, ${1 \over 3}$, ${1 \over 4}$,....................$\,{1 \over {n + 1}}$ respectively, then find the values of ${S_1}^2 + {S_2}^2 + {S_3}^2 + ....... + {S^2}_{2n - 1}$
Correct Answer: $${{{}^n(2n + 1)\,(4n + 1) - 3} \over 3}$$
1991
Q444
JEE Advanced
Numerical
14 Mar 2026
Let p be the first of the n arithmetic means between two numbers and q the first of n harmonic means between the same numbers. Show that q does not lie between p and $\,{\left( {{{n + 1} \over {n - 1}}} \right)^2}\,p$.
Correct Answer: solve it
1990
Q445
JEE Advanced
MCQ
14 Mar 2026
The number ${\log _2}\,7$ is
A.
an integer
B.
a rational number
C.
an irrational number
D.
a prime number
1990
Q446
JEE Advanced
Numerical
14 Mar 2026
If ${\log _3}\,2\,,\,\,{\log _3}\,({2^x} - 5)\,,\,and\,\,{\log _3}\,\left( {{2^x} - {7 \over 2}} \right)$ are in arithmetic progression, determine the value of x.
Correct Answer: 3
1988
Q447
JEE Advanced
MCQ
14 Mar 2026
Sum of the first n terms of the series ${1 \over 2} + {3 \over 4} + {7 \over 8} + {{15} \over {16}} + ............$ is equal to
A.
${2^n} - n - 1$
B.
$1 - {2^{ - n}}$
C.
$n + {2^{ - n}} - 1$
D.
${2^n} + 1$
1988
Q448
JEE Advanced
MSQ
14 Mar 2026
If the first and the $(2n-1)$st terms of an A.P., a G.P. and an H.P. are equal and their $n$-th terms are $a,b$ and $c$ respectively, then
A.
$a = b = c$
B.
$a \ge b \ge c$
C.
$a + c = b$
D.
$ac - {b^2} = 0$
1988
Q449
JEE Advanced
Numerical
14 Mar 2026
The sum of the first n terms of the series ${1^2} + {2.2^2} + {3^2} + {2.4^2} + {5^2} + {2.6^2} + .........$ is
$n\,\,{\left( {n + 1} \right)^2}/2,$ when $n$ is even. When $n$ is odd, the sum is .............
$n\,\,{\left( {n + 1} \right)^2}/2,$ when $n$ is even. When $n$ is odd, the sum is .............
Correct Answer: $${{{n^2}\left( {n + 1} \right)} \over 2}$$
1986
Q450
JEE Advanced
Numerical
14 Mar 2026
The solution of the equation $lo{g_7}$ $lo{g_5}$ $\left( {\sqrt {x + 5} + \sqrt x } \right) = 0$ is .............
Correct Answer: 4