Sequence and Series

128 Practice MCQs available for CA Foundation

Paper

Paper 3: Quantitative Aptitude

Exam Weightage

4-6 Marks

Key Topics

Arithmetic & Geometric Progressions

This chapter covers Arithmetic Progressions (AP) and Geometric Progressions (GP). Students learn how to find the nth term, sum of n terms, arithmetic/geometric means, and sum to infinity of a GP.

Exam Strategy Tip

For complex 'sum of series' questions, a great hack is to substitute n = 1 and n = 2 into the question and the options to see which one matches, completely bypassing the formula.

All 128 Questions

1762

If the sum of '$n$' terms of an AP (Arithmetic Progression) is $2n^2$, the fifth term is ____.

1763

The sum of first $n$ terms an AP is $3n^2+5n$. The series is:

1757

If $2+6+10+14+.........+x=882$ then the value of $x$ is

1758

If the sum of five terms of AP is $75$. Find the third term of the series.

1759

The $20^{th}$ term of arithmetic progression whose $6^{th}$ term is $38$ and $10^{th}$ term is $66$ is:

1760

Divide $69$ into $3$ parts which are in A.P. and are such that the product of first two parts is $483$.

1761

The number of terms of the series: $5+7+9+...$ must be taken so that the sum may be $480$.

1766

A person pays $975$ in monthly installments, each installment is less than formed by $5$. The amount of $1^{st}$ installment is $100$. In what time will the entire amount be paid?

1767

If the sum of $n$ terms of an AP is $(3n^2-n)$ and its common difference is $6$, then its $1^{st}$ term is:

1768

Insert two arithmetic means between $68$ and $260$.

1769

If the $p^{th}$ term of an A.P. is '$q$' and the $q^{th}$ term is '$p$', then its $n^{th}$ term is

1770

The sum of the series $-8,-6,-4,.........n$ terms is $52$. The number of terms $n$ is

1771

The value of $K$, for which the terms $7K+3, 4K-5, 2K+10$ are in A.P., is

1773

If $p^{th}$ term of an AP is $q$ and its $q^{th}$ term is $p$, then what will be the value of $(p+q)^{th}$ term?

1774

How many numbers between $74$ and $25,556$ are divisible by $5$?

1775

If $9^{th}$ and $19^{th}$ term of an AP are $35$ and $75$, respectively, then its $20^{th}$ term is:

1776

Find the $17^{th}$ term of an AP series if $15^{th}$ and $21^{st}$ terms are $30.5$ and $39.5$ respectively.

1777

If $n^{th}$ term of an AP series is $7n-2$, then sum of '$n$' terms is:

1778

Find the value of '$x$' for the following data $1+7+13+19.........+x=225$

1782

If fourth term of A.P. series is zero, then what is the ratio of twenty-fifth term of eleventh term?

1783

If $8^{th}$ term of an AP is $15$, the Sum of the $15$ its term is

1784

For what value of $x$; the sequence $x+1, 3x, 4x+2$ are in AP?

1785

The $n^{th}$ element of the series $3,5,7,...$ is

1786

If $1+3+5+.........+n$ terms $= \frac{n^2}{2}$ If $2+4+6+.........+50$ terms $= 51$ then the value of '$n$' is

1787

If $6^{th}$ and $13^{th}$ term of an A.P are $15$ and $36$ respectively the A.P is

1788

The value of $K$, for which the terms $7K+3$, $4K-5$, $2K+10$ are in A.P., is

1790

The first term of an A.P. is $100$ and the sum of whose first $6$ terms is $5$ times the sum of the next $6$ terms, then the c.d. is:

1791

The sum of $n$ terms of an A.P. is $3n^2+n$; then its $p^{th}$ term is

1792

If three AM's between $3$ and $11$, they are

1793

The first and the last term of an AP are $-4$ and $146$. The sum of the terms is $7171$. The number of terms is

1796

The sum of the first $3$ terms in an AP is $18$ and that of the last $3$ is $28$. If the AP has $13$ terms, find sum of the middle three terms?

1798

The ratio of sum of first $n$ natural numbers to sum of cubes of first $n$ natural numbers is

1799

Sum of progression $(a+b)$, $(a-b)$, $(a-3b)...n$ term is

1800

Find the sum of first twenty-five terms of A.P. series whose $n^{th}$ term is $\left(n+\frac{2}{5}\right)$

1795

Insert $4$ A.M.'s between $3$ and $18$:

1801

The first and fifth term of an A.P. of $40$ terms are $-29$ and $-15$ respectively. Find the sum of all positive terms of this A.P

1802

If the common difference of an AP equals to the first term, then the ratio of its $m^{th}$ term and $n^{th}$ term is:

1803

Find the value of $1+2+3+...+105$

1764

The $n^{th}$ term of the series $9,7,5,...$ and $15,12,9,...$ are same. Find the $n^{th}$ term?

1772

If the ratio of sum of $n$ terms of two APs is $(n-1):(n+1)$, then the ratio of their $n^{th}$ terms is

1779

In an arithmetic progression, the seventh terms is $x$, and $(x+7)^{th}$ term is zero. Then $x^{th}$ term is

1780

If the second and eight terms of an arithmetic progression (AP) are equal to constant $a$, then the sum of first $n$ terms of this AP is equal to

1781

The $3^{rd}$ term of arithmetic progression is $7$ and Seventh term is $2$ more than thrice of third term. The common difference is

1789

Which term of the AP $64, 60, 56, 52...$ is $0$

1797

If the sum of $n$ terms of an AP is $2n^2$, then $5^{th}$ term is

1825

Sum up to infinity of series. $1 + \frac{1}{2} + \frac{1}{3} + \frac{1}{4} + \frac{1}{8} + \frac{1}{9} + \frac{1}{16} + \frac{1}{27} + \dots$

1826

Sum the series $\frac{1}{5} + \frac{1}{5^2} + \frac{1}{5^3} + \dots + \frac{1}{5^n}$

1827

Find no. of terms of the series $25, 5, 1, \dots, \frac{1}{3125}$

1828

Three numbers in G.P. with their sum 130 and their product 27,000 are:

1829

In a geometric progression, that $3^{rd}$ and $6^{th}$ terms are respectively 1 and $-1/8$. The term $(a)$ and common ratio are respectively.

1830

If the sum and product of three numbers in G.P. are 7 and 8 respectively, then $4^{th}$ term of the series is

1831

The $3^{rd}$ term of a G.P. is $2/3$ and the $6^{th}$ term is $2/81$ then the $1^{st}$ term is

1832

The sum of series $7 + 14 + 21 + \dots$ to $17^{th}$ term is:

1833

The largest value of $n$ for which $1 + \frac{1}{2} + \frac{1}{2^2} + \dots + \frac{1}{2^{n-1}} < 0.998$ is

1834

The sum of first 8 terms of a G.P is five times the sum of the first 4 terms. Find the common ratio?

1835

In a GP $5^{th}$ term is 27 and $8^{th}$ term is 729. Find its $11^{th}$ term?

1836

If $4^{th}, 7^{th}$ and $10^{th}$ terms of a Geometric Progression are $p, q$ and $r$, respectively, then:

1837

Given an infinite geometric series with first term '$a$' and common ratio '$r$'. If its sum is 4 and the second term is $\frac{3}{4}$, then one of correct option is

1838

If for an infinite geometric progression, first term is '$a$', common ratio is '$r$', the sum is 8 and the second term is $\frac{7}{8}$, then

1839

For what values of $X$, the number $\frac{-2}{7}, X, \frac{-7}{2}$ are in G.P.?

1805

If the sum of $n$ terms of an AP is $3n^2-n$ and its common difference is $6$, then its $1^{st}$ term is

1806

Sum lying from $100$ to $300$ which is divisible by $4$ and $5$ is

1808

Sum of $n$ terms of two AP's are in the ratio $(3n+5):(5n+3)$ then ratio of their $10^{th}$ term

1809

If the $p^{th}$ term of an A.P. is 'q' and the $q^{th}$ term is 'p', then its $r^{th}$ term is:

1810

In AP $T_p=q$ and $T_q=p$ then $T_{p+q}=$

1811

If the sum of $n$ terms of an A.P. be $2n^2+5n$, then its '$n^{th}$' term is:

1812

If $20$ AMs. are inserted between $3$ and $51$ then sum of these $20$ A.M.s is

1813

The first, second and seventh term of an AP are in G.P. and the common difference is $2$, the $2^{nd}$ term of A.P. is:

1814

The $4^{th}$ term of an A.P. is three times the first and the $7^{th}$ term exceeds twice the third term by $1$. Find the first term 'a' and common difference 'd'.

1815

Find the sum of all natural numbers betn $250$ and $1000$ which are exactly divisible by $3$:

1816

A person puts Rs. $975$ in monthly instalment, each instalment is less than former by Rs. $5$. The amount of first instalment is Rs. $100$. In what time will the entire amount be paid?

1817

If the sum of $n$ terms of an A.P. is $(3n^2-n)$ and its common difference is $6$, then its first term is:

1818

If $(x+1)$, $3x$, $(4x+2)$ are in A.P. Find the value of $x$

1819

Divide 144 into three parts which are in AP and such that the largest is twice the smallest, the smallest of three numbers will be:

1820

If $8^{th}$ term of an AP is 15, the sum of the 15 terms is

1821

For what value of $x$, the sequence $x+1, 3x, 4x+2$ are in AP?

1822

The $n^{th}$ term of the series whose sum to $n$ terms is $3n^2+2n$ is

1823

In a G.P., if the fourth term is '3' then the product of first seven terms is

1824

$y = 1 + x + x^2 + \dots \infty$, then $x =$

1840

Find the three numbers in G.P. whose sum is 19 and product is 216.

1845

Given: $P(7, k) = 60 P(7, k-3)$. Then: $k = $

1846

If the $p^{th}$ term of a G.P. is $x$ and the $q^{th}$ term is $y$, then find the $n^{th}$ term:

1847

The sum of the series $0.5+0.55+0.555+\dots$ to $n$ terms is:

1848

The second term of a G.P is $24$ and the fifth term is $81$. The series is

1849

The series $1+10^{-1}+10^{-2}+\dots$ to $\infty$ is

1867

The sum of $m$ terms of the series $1+11+111+\dots$ up to $m$ terms, is equal to:

1868

If $(b+c-a), (c+a-b), (a+b-c)$ are in AP then $a, b, c$ are in:

1869

If the AM and GM of two numbers is $6.5$ and $6$ the no.'s are:

1870

If AM and HM for two numbers are $3$ and $3.2$, respectively. GM will be:

1872

The $n^{th}$ term of the series $3 + 7 + 13 + 21 + 31 + \dots$ is

1873

The numbers $x$, $8$, $y$ are in G.P. and the numbers $x$, $y$, $-8$ are in A.P. The values of $x$ and $y$ respectively shall be

1874

If $a^x = b^y = c^z$ and $a, b, c$ are in G.P., the $x, y, z$ are in

1876

If $a^x = b^y = c^z = e^{1/2}$ then $a, b, c$ are in GP then $x, y, z$ are in

1842

The sum of the first two terms of a GP is $5/3$ and the sum of infinity of the series is 3. The common ratio is

1850

In a GP, if fourth term is $3$ then the product of first seven terms is

1853

In a G. P, sixth term is $729$ and the common ratio is $3$, then the first term of G.P is

1854

In a geometric progression, the second term is $12$ and sixth term is $192$. Find $11^{th}$ term.

1856

If $5^{th}$ term of G.P. is $32$ and $8^{th}$ term of G.P. is $8$ then $6^{th}$ term of G.P. is

1857

Which term of the sequence $2, 4, 8, 16 \dots$ is $2048$?

1858

The $5^{th}$ and $8^{th}$ terms of a GP series is $27$ and $729$. Then find the $10^{th}$ term.

1859

Four Geometric Means between $4$ and $972$ are

1860

The sum up to infinity of the series $S = \frac{1}{1 \cdot 2} + \frac{1}{2 \cdot 3} + \frac{1}{3 \cdot 4} + \dots$ is

1861

The $3^{rd}$ term of a G.P is $\frac{2}{3}$ and $6^{th}$ term is $\frac{2}{81}$, then the first term is

1862

Find the sum to infinity of the following series: $1 - 1 + 1 - 1 + \dots \infty$

1863

Find the product of: $(243), (243)^{\frac{1}{6}}, (243)^{\frac{1}{36}}, \dots \infty$

1864

The sum of the first eight terms of a G.P. is five times the sum of the first four terms; then the common ratio is:

1865

For what values of $x$, the number $-\frac{2}{7}, x, -\frac{7}{2}$ are in G.P.?

1866

If $a^{\frac{1}{x}} = b^{\frac{1}{y}} = c^{\frac{1}{z}}$ and $a,b,c$ are in GP then $x, y, z$ are in

1875

If $x, y$ and $z$ are the terms in G.P., then the term $x^2 + y^2, xy + yz, y^2 + z^2$ are in

1843

The sum of the infinite series $1 + \frac{2}{3} + \frac{4}{9} + \dots$ is

1851

In a G.P. If the third term of a GP is $\frac{2}{3}$ and $6^{th}$ term is $\frac{2}{81}$, then the first term is

1852

Sum upto infinity series $1 + \frac{1}{2} + \frac{1}{4} + \frac{1}{8} + \dots + \frac{1}{2^n} + \dots$ is

1855

The sum of first eight terms of geometric progression is five times the sum of the first four terms. The common ratio is

1871

The sum of three numbers in a geometric progression is $28$. When $7$, $2$ and $1$ are subtracted from the first, second and the third numbers respectively, then the resulting numbers are in arithmetic progression. What is the sum of squares of the original three numbers?

1877

The sum of the first two terms of an infinite geometric series is $15$ and each term is equal to the sum of all the terms following it, then the sum of the series is

1879

Three numbers are in AP and their sum is $21$. If $1, 5, 15$ are added to them respectively, they form a G.P. The numbers are

1880

The sum of three numbers in G.P. is $70$. If the two extremes by multiplied each by $4$ and the mean by $5$, the products are in AP. The numbers are

1881

If $a, b, c$ are in AP and $x, y, z$ are in GP, then the value of $x^{(b-c)} y^{(c-a)} z^{(a-b)}$ is

1882

The sum of the series $1 + 11 + 111 + \dots$ to $n$ terms is

1883

The sum of the following series $4 + 44 + 444 + \dots$ to $n$ terms is:

1884

Find the sum of the series. $243 + 324 + 432 + \dots$ to $n$ terms

1844

Find the sum to $n$ terms of the series: $7+77+777+\dots$ to $n$ terms:

1878

$\sum n^3$ defines:

1841

The $n^{th}$ term of the sequence $-1, 2, -4, 8, \dots$ is

1794

If the sum of $n$ terms of an A.P. is $3n^2-n$ and its common difference is $6$, then its third term is:

1804

The first and last terms of an arithmetic progression are $5$ and $905$. Sum of the terms is $45,955$. The number of terms is

1807

A man starts his job with a certain monthly salary and earns a fixed increment every year. If his salary was $1,500$ after $4$ years of service and $1,800$ after $10$ years of service, what was his starting salary and what is the annual increment in rupees?

1765

A person pays $975$ in monthly installments, each installment is less than former by $5$. The amount of $1^{st}$ installment is $100$. In what time will the entire amount be paid?

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