Number Series, Coding and Decoding

217 Practice MCQs available for CA Foundation

Paper

Paper 3: Quantitative Aptitude

Exam Weightage

5 Marks

Key Topics

Number series, Coding & Decoding, Odd man out

This chapter covers Number series, Coding & Decoding, Odd man out and is part of Paper 3: Quantitative Aptitude in the CA Foundation exam.

Exam Strategy Tip

This topic carries 5 Marks weightage. Focus on understanding core concepts rather than memorizing.

Key Terms

Index Number

A statistical device for measuring changes in the magnitude of a group of related variables (like prices or production) over time.

Weighted Average Method

An inventory costing method that calculates the cost of ending inventory and COGS by dividing the total cost of goods available for sale by the total number of units available, resulting in a single average cost applied to all units.

Arithmetic Progression (AP)

A sequence of numbers in which each term after the first is obtained by adding a fixed constant (called the Common Difference, d) to the preceding term. The general term is Tn = a + (n−1)d, and the sum is Sn = n/2 × [2a + (n−1)d].

Geometric Progression (GP)

A sequence of numbers where each term after the first is obtained by multiplying the preceding term by a fixed non-zero constant called the Common Ratio (r). General term: Tn = ar^(n−1). Sum: Sn = a(rⁿ−1)/(r−1) for r ≠ 1.

Matrix

A rectangular arrangement of numbers (elements) in rows and columns, enclosed in brackets. An m × n matrix has m rows and n columns. Matrices support addition, subtraction, and multiplication (subject to compatibility conditions).

Comparison Tables

Cardinal vs Ordinal Utility: Measuring Satisfaction Promissory Note vs Bill of Exchange: Negotiable Instruments

All 217 Questions

The number in place of question mark in:

\displaystyle 7, 26, 63, 124, 215, ?, 511

Find missing term

\displaystyle 7, 26, 63, 124, 215, 342, ?

Which number should come next

\displaystyle 7, 26, 63, 124, 215, 342, ?

If CLOCK is coded as 34235 and TIME as 8679, then MOTEL is coded as:

If MOUSE, is coded as 34651 and KEY is coded as 217, then how will YES be coded?

In a certain code language PREMONITION is written as

\displaystyle 68530492904

, how will the word MONITOR be written in that code language?

Find the odd man one from the following:

Find the odd man out:

\displaystyle 34, 105, 424, 2123, 12756

\displaystyle 41, 43, 47, 53, 61, 71, 83, 95

Find the odd man out in the following series:

\displaystyle 190, 145, 136, 352, 460, 324, 631, 244

Find odd one out of the series:

\displaystyle 16, 25, 36, 72, 144, 196

\displaystyle 225

Find odd man out of the following series

\displaystyle 41, 43, 47, 53, 61, 71, 73, 81

Find wrong number of the series

\displaystyle 22, 37, 52, 67, 84, 97

Find odd man out of the following series

\displaystyle 15, 21, 63, 81, 69

Identify the next number in the following series: 2, 8, 26, 62, 122, 212, _______

Find the missing number in the given series: 4, 18 ______, 100, 180, 294, 448

Find the odd man out from the following: 445, 221, 109, 46, 25, 11, 4

In a certain code "CH4IR" is written as "GL8MV". How is "1N5T4GR4M" is written in that code?

A certain code "564" means "all the best", "736" means "best of luck" and "423" means "all is luck". Which of the following is the code for "luck"?

Complete the given series: 0, 6, 24, 60, 120, 210,

Find the odd one out in the series: 2, 5, 10, 17, 26, 37, 50, 64.

If in a certain language, MADRAS is coded as NBESBT. How is DELHI coded in that language?

In a certain code, GLAMOUR is written as IJCNMWP and MISRULE is written as OGUSSNC, then how will MUSICAL be written in that code?

In the following series, one term is wrong. Find out the wrong term. 48, 50, 82, 170, 290

Which of the followings is odd one?

Find the odd number in the following series: 7, 11, 13, 15, 19, 23, ...

The next term of the series 1, 7, 17, 31, 49, 71, ______ is

If in a certain code language PAINT is coded as 74128 and ACCEPT is coded as 455978, what will be the code for PATIENT?

If in a certain language, MONKEY is coded as NNOJFX, how is PUZZLE coded in that language?

Find the missing number of the series

\displaystyle 48, 24, 96, 48, 192, \dots ?

Find the missing term of the following series

\displaystyle 3, 7, 15, ?, 63, 127

Find next term of the letter series A, CD, GHI, UVWXY, ______.

Find next term of the series

\displaystyle 1, 3, 4, 8, 15, 27, ?

In a certain Code Language BEAT is written as YYZG, then what will be Code for MILD?

Find the missing term of the following series

\displaystyle 3, 15, ?, 63, 99, 143

Find next term of the series

\displaystyle 10, 69, 236, 595, ?

If 'FROZEN' is decoded as 'OFAPSG'. Tick the right option that depicts 'MOLTEN' written in this way?

\displaystyle 105, 115.5, 150, 162.5, 203, ?

Find out the next number in the following series

\displaystyle 7, 11, 13, 17, 19, 23, 25, 29, ?

In certain code language, if TOUR is written as 1234, CLEAR is written 56784 and SPACE is written as 90847, find the code for CARE?

Identify the next number in the following series: 2, 8, 26, 62, 122, 212, _______

Find the missing number in the given series: 4, 18 ______, 100, 180, 294, 448

Find the odd man out from the following: 445, 221, 109, 46, 25, 11, 4

In a certain code "CH4IR" is written as "GL8MV". How is "1N5T4GR4M" is written in that code?

A certain code "564" means "all the best", "736" means "best of luck" and "423" means "all is luck". Which of the following is the code for "luck"?

Complete the given series: 0, 6, 24, 60, 120, 210,

Find the odd one out in the series: 2, 5, 10, 17, 26, 37, 50, 64.

If in a certain language, MADRAS is coded as NBESBT. How is DELHI coded in that language?

In a certain code, GLAMOUR is written as IJCNMWP and MISRULE is written as OGUSSNC, then how will MUSICAL be written in that code?

In the following series, one term is wrong. Find out the wrong term. 48, 50, 82, 170, 290

Which of the followings is odd one?

Find the odd number in the following series: 7, 11, 13, 15, 19, 23, ...

The next term of the series 1, 7, 17, 31, 49, 71, ______ is

If in a certain code language PAINT is coded as 74128 and ACCEPT is coded as 455978, what will be the code for PATIENT?

If in a certain language, MONKEY is coded as NNOJFX, how is PUZZLE coded in that language?

Find out the next number in the following series

\displaystyle 7, 11, 13, 17, 19, 23, 25, 29

Find the next number in the series:

\displaystyle 7, 23, 47, 119, 167

Complete the series

\displaystyle 4, 16, 36, 64, 100, \_\_\_\_\_\_

Complete the series

\displaystyle 4, 16, \_\_\_\_\_\_, 256, 1024

Find the missing value in the series

\displaystyle 0, 2, 3, 6, 10, 17, 28, ?, 75

Find the missing value in

\displaystyle 3, 8, 18, ?, 78

Find the wrong term in: G4T, J10R, M20P, P43N, S90L.

Find the next term

\displaystyle 1, 5, 21, 57, \_\_\_\_\_\_

Find the next term

\displaystyle \frac{1}{2}, \frac{3}{4}, \frac{5}{7}, \frac{7}{11}, \frac{2}{4}, \frac{4}{8}, \frac{16}{?}

Find the missing term: P3C, R5E, T8I, V12L, ?

Choose the missing term in the series.

\displaystyle 1, 1, 8, 4, 27, \_\_\_\_\_\_, 64, 16

The wrong term in the series

\displaystyle 225, 196, 169, 144, 121, 100, 77, 64

What comes at the last place in R, U, X, A, D, \_\_\_\_\_\_?

The missing term of the series

\displaystyle 4, 13, \_\_\_\_\_\_, 49, 76

\displaystyle 7, 26, 63, 124, 215, 342, \_\_\_\_\_\_?

\displaystyle 4, 6, 9, 13.5, \_\_\_\_\_\_, 30.375

Find out the next term

\displaystyle -7, 11, 27, 63, 127, \_\_\_\_\_\_

Find the next terms-

\displaystyle 3, 7, 15, 31, ?, 127

Find out the next term

\displaystyle -6, 13, 28, 59, ?

Find the missing number in the following series?

\displaystyle 3, 5, 5, 19, 7, 41, 9, ?, 11, 109

Find the next number in the given sequence?

\displaystyle 11, 17, 39, 85, ?, 281, 447

Find the next number in the series: Q1F, S2E, U6D, W21C, \_\_\_\_\_\_?

Find the missing number

\displaystyle 2, 3, 8, ?, 3968

(hint: preceding number's square then minus 1)

What comes next in the series: FMAMJJASON?

In a code TEACHER is written as VGCJEGT, How is CHILDREN written in that code.

Find the missing value in the series :

\displaystyle 51, 52, 60, 87, 151, \_\_\_\_\_\_, 492

AZ, GT, MN, \_\_\_\_\_\_, YB, EV. The value of blank spaces (\_\_\_\_\_\_) will be:

Find the next number in the series

\displaystyle 2, 5, 11, 23, 47, \_\_\_\_\_\_

\displaystyle 18, 24, 21, 27, ?, 30, 27

\displaystyle 5, 7, 11, ?, 35, 67

Find the missing term of the number series

\displaystyle 24, 60, 120, 210, ?

Find the missing number of the series

\displaystyle 22, 24, 28, ?, 52, 84

Find missing number of series

\displaystyle 1, 5, 13, 25, 41, \_\_\_\_\_\_

Find the missing term of the series

\displaystyle 17, 14, 15, 12, 13, ?, ?

Find the missing term

\displaystyle 9, 27, 31, 155, 161, 1127, ?

Find missing term of the alphabet series ABD, DGK, HMS, MTB, SBL?

Find next number in the following series

\displaystyle 7, 11, 13, 17, 19, 23, 25, 29?

Find next term of the letter series QPO, NML, KJI, HGF, ______.

Find the missing term of series

\displaystyle 27, 32, 30, 35, 33, ?

Find out the letter series AZY, EXW, IVU, ?

Find next number in the following series

\displaystyle 7, 11, 13, 17, 19, 23, 25, 29, ?

Which number should come next

\displaystyle 7, 13, 13, 14, 19, 15?

Find out the next term of the series

\displaystyle 4, 25, 121, 289, ?

Find next term of the series

\displaystyle 3, 10, 29, 66, 127, ?

The missing term of series

\displaystyle 11, 10, ?, 27, 66, 198.5

What comes at last place in R, U, X, A, D, ?

Find missing term of the series

\displaystyle 2, 3, 3.5, 10, 13, ?, 33, 172, 177

Find the missing term in each of the following series:

\displaystyle 6, 13, 25, 51, 101.

Find the missing term in each of the following series :

\displaystyle 28, 33, 31, 36, 34, ?

Find the missing term of the following series:

\displaystyle 7, 26, 63, 124, 215, 342?

Find the next alphabet series in the given sequence? ALN, DNP, GPR?

Find the missing number in the following series?

\displaystyle 2, 15, 10, 17, 26?

Which number will come next in the following series?

\displaystyle 675, 623, 573, 525?

Identify the sequence of letters and find out the missing number. AGM, DJP, HNT, ______.

Find next number of the series

\displaystyle 7, 23, 47, 119, 167

Find next term of the series A5A, C10C, E15E, E20G ______.

In the following series, which number will replace the question mark:

\displaystyle 23, 29, 31, 37, 41, 43, ?

In the following letter-series some letters are missing. The missing letters are given in the proper sequence as one of the alternatives. Find the correct alternative.

\displaystyle ab - dca - abc - bca - c

Find next term of the series

\displaystyle 4, 9, 16, 25, 36, 49, ?

Find the missing value in the series:

\displaystyle 51, 52, 60, 87, 151, ______. 492.

If DELHI is coded as EFMII then JAIPUR is coded as:

Find next term of the series

\displaystyle 1, 3, 14, 30, 55, 91, ?

In a certain code, RIPPLE is written as 613382 and LIFE is written as 8192. How PILLER is coded?

In a certain code '256' means 'you are good', '637' means 'we are bad' and '358' means 'good and bad'. Which digit represents 'and' in that code?

If LOSE is coded as 1357 and GAIN is coded as 2468, what do figure 82146 for?

If PLAY is coded as 8123 and RHYME is coded as 49367. What will be code of MALE?

If FRAME is coded as 0618011305 then ARISE is coded as:

If HONEY is coded as JQPGA, which word is code as VCTIGVU?

If in a Certain language, MADRAS is coded as NBESBT. How DELHI is coded in that code?

In a certain code MADRAS is NBESBT now DELHI is coded as:

If HEALTH is written as IFBMUL, then how will NORTH be written in that code?

In a certain code RIPPLE is written as 613382, and LIFE is written as 8192. How will RIFFLE be written in that code?

In a code, MENTION is written as LNEITNO. How is PRESENT written in that code?

In a certain code "THANKS" is written as " SKNHTA" then how is "STUPID" written?

LOTUS is coded as 14682 and STRANGE is coded as 2690753. How will you code GESTURE?

Code for word EARTH is 16235 and VENUS is 91784 what is code for SATURN?

In a certain code, RIPPLE is written as 613382 and LIFE is written as 8192. How is PILLER written in that code?

If ROSE is coded as 6821, CHAIR is coded as 73456 and PREACH is coded as 961473, what will be the code for SEARCH?

In a certain code SIKKIM is written as THLJLIL then how is TRAINING written in that code?

In certain language, PEAR is coded as 7519, and TOIL is coded as 2693, then how DOCTOR be written in that code?

In a certain code word "STATEMENT" is written as "TNEMETATS". How "POLITICAL" coded:

In a certain code INACTIVE is written as VITCANIE, How is COMPUTER written in the same code

If TAP is coded as SZO in a language, then how is FRIEND coded in same language?

If GARDEN is coded as 325764 and WATER as 92165, how can we code the word WARDEN in the same way?

If F=6, MAT=34, then how much is CAR?

In a certain code language 'EXAM' is coded as 39 'PAPER' is coded at 51 then PASS is coded as

In a certain language MADRAS is coded as NBESBT, how BOMBAY is coded?

\displaystyle 32

\displaystyle 49

, then SOME will be equal to

In a certain Code DECEMBER is written as ERMBECED. Which word will be written as ERMBVENO in that code?

If SUMMER is coded as RUNNER the code for WINTER will be

In a certain code KAVERI is written as VAKIRE. How is MYSORE written in that code?

In a certain language TWINKLE is written as SVHOJKD, then how would FILTERS be written in the same code?

If 'MEAT' is written as 'TEAM', then 'BALE' is written as

In a certain language, FLOWER is coded UOLDVI, then how is TERMINAL coded in that language?

If TWENTY is written as 863985 and ELEVEN is written as 323039, then TWELVE can be coded

If 'LOSE' is coded 1357 and 'GAIN' is coded as 2468 What do the figure 82146 for

\displaystyle B = 2

\displaystyle BAG = 10

\displaystyle BOX = ?

If DELHI is coded as 73541 and CALCUTTA as 82589662, then CALICUT be coded as?

In a certain code, "Delhi is capital" is coded as "7 5 9" "capital are beautiful" is coded as "3 6 9", "Delhi is beautiful" is coded as "6 7 5", "Patna also capital" is coded as "9 2 4". What is code for "beautiful"?

Find the missing term 5760, 960, ?, 48, 16, 8

If 'SYSTEM' is coded as 131625 then 'TERMS' will be coded as ?

In a certain code 'SOUTHERN' is written as 'UVPPTMQDG'. How is 'MARIGOLD' written in that code?

In a certain code 'PRISM' is written as 'OSHTL' and 'RUBLE' is written as 'QVAMD'. How will 'WHORL' be written in that code?

\displaystyle Z = 52

\displaystyle ACT = 48

\displaystyle BAT = ?

\displaystyle E = 5

\displaystyle READ = 7

, then what is the code of 'DEAR'?

In a code TELEPHONE is written as ENOHPELET. How is ALIGATOR coded?

In a certain code, 'CLOUD' is written as 'GTRKF'. How is 'SIGHT' written in that code?

In a code, TEACHER is written as VGCEJGT. How is CHILDREN written in that code?

In a certain code, '253' means 'books are old'; '546' means 'man is old' and '378' means 'buy good books'. What stands for 'are' in that code?

If SUMMER is coded as RUNNER, the code for WINTER will be

If GOODNESS is coded as HPOODTR, then how GREATNESS can be written in that code?

In certain code language, if TOUR, is written as 1234, CLEAR is written 5678 and SPACE is written as 90847, Find the code for TEARS ?

If ROSE is coded as 6821, CHAIR is coded as 73456 and PREACH is coded as 961473, what will be the code for RESEARCH?

In certain code language, BOARD is coded as CQDVL, what is the code for CONSULTING?

In a certain code if CAMP is written as 9, then in the word TEAM be coded as?

The cost function for the production of

\displaystyle x

units of a commodity by

\displaystyle C(x) = 2x^2 + 15x + 36

. The total cost will be minimum when

\displaystyle x

TWENTY is written as 863985 and ELEVEN is written as 323039, then TWELVE can be coded.

If PLAY is coded as 8123 and RHYME is coded 49367. What will be code of REAL?

If in a code, MIND becomes KGLB and ARGUE becomes YPESN, then what will DIAGRAM be in that code?

\displaystyle A = 2

\displaystyle M = 26

\displaystyle Z = 52

If 'sky' is 'star', 'star' is 'cloud', 'cloud' is 'earth', 'earth' is 'tree' and 'tree' is 'book'. Then where do the birds fly?

If MACHINE is coded as

\displaystyle 19 - 7 - 9 - 14 - 15 - 20 - 11

, how will you code DANGER?

If HEALTH is written as GSKZDG, then how will NORTH be written in that code?

In a certain code, TEACHER is written as VGCEJGT. How is CHILDREN written in that code?

If 'INSURE' is coded as

\displaystyle 951395

, then how will 'PATRIOT' be coded?

If in a certain code '493' means 'Friendship difficult challenge', '961' means, 'Struggle difficult Exam', and '178' means 'Exam believable subject', then which digit is used for 'believable'?

If 'GOAL' is coded as 'HPBM' and 'FROCK' is coded as 'GSPTL' then how will 'LOFAR' be coded?

If GARDEN is coded as

\displaystyle 325764

\displaystyle 92165

, how can we code the word WARDEN in the same way?

\displaystyle E = 6

\displaystyle MAT = 34

, then how much is CAR?

In a certain code INACTIVE is written as VTCANIE, how is COMPUTER written in the same code?

\displaystyle A = 26

\displaystyle SUN = 27

In a certain code language, '123' means 'bright little boy', '145' means 'tall big boy' and '637' means 'beautiful little flower'. Which digit in that language means 'bright'?

Find odd man out of the following series

\displaystyle 15, 21, 63, 81, 69

Find odd man out of the following

\displaystyle 7, 9, 13, 17, 19

\displaystyle 4, 12, 44, 176, 890...

Which of the following is odd one?

Find the odd man out

\displaystyle 5, 10, 17, 27, 37

SYSTEM is coded as

\displaystyle 131625

then TERMS is will be coded as?

Find the odd one out:

\displaystyle 1, 5, 14, 30, 49, 55, 91

Which of the following is the odd one:

\displaystyle 6, 9, 15, 21, 24, 26, 30

Find out the odd man out in the Sequence

\displaystyle 8, 25, 64, 125, 216

In a series of letters, which one is the odd one out: BDFH, JLNP, RTVX, ZBDE?

Find the odd man out from the following series :

\displaystyle 7, 23, 47, 119, 171, 287

Find the odd man out

\displaystyle 1, 4, 9, 16, 20, 36, 49

Find the odd man out of the series

\displaystyle 16, 25, 36, 72, 144, 196, 225

Find the odd man out

Find the odd man out of the series

\displaystyle 5, 10, 17, 25

Find odd one out of the series

\displaystyle 7, 9, 11, 12, 14, 15

Find odd one out of the series

\displaystyle 37, 45, 49, 65, 79

Find out the odd one out of the series

\displaystyle 5, 27, 61, 122, 213, 340, 509

Find the wrong term of the series

\displaystyle 121, 143, 165, 186, 209

Find odd man out of the series

\displaystyle 145, 197, 257, 325, 399

Which of the following is odd one

Find out the wrong number

\displaystyle 2, 10, 18, 54, 162, 486, 1458

Find out the wrong number

\displaystyle 10, 14, 28, 32, 64, 68, 132

Find wrong number of the series

\displaystyle 1, 5, 9, 7, 11, 15, 12, 17

Find odd man out of the following series

\displaystyle 3, 4, 10, 32, 136, 685, 4116

Find the odd man out:

\displaystyle 34, 105, 424, 2125, 12755

Find odd man out:

\displaystyle 34, 105, 424, 2123, 12756

Find odd man out of the following:

Choose the odd numerical pair group

Find odd man out of the series

\displaystyle 16, 25, 36, 72, 144, 196, 225

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