11th Class Mental Ability Series Notes - Series

Notes - Series

Category : 11th Class

Learning Objectives

Introduction
Number Series
Letters Series
Mixed Series

Introduction

In a verbal series, words, letters or digits are given in a specific sequence or order. This section deals with questions in which series of numbers or letters are given. The term .follows a certain pattern throughout. Find out the next word, letter or digit to complete the given series. As it is, there is no set pattern and each question may follow a different pattern or sequential arrangement of letters or digits. Which you have to detect using common series and reasoning ability.

There are mainly three types of verbal series completion patterns.

Number series
Letter series
Mixed series

Type-1

Number Series

Introduction

In this type of series, instead of letters, numbers or digits are used. Number series is divided into 4 types as given below:

(i) Skipping the numbers in same set order.

(ii) Addition, subtraction, multiplication or division of numbers to get the next numbers in the series.

(iii) Logical transport of numbers.

(iv) Increase/decrease in numbers in a specific order.

Example:

Which number would replace the question mark (?) in the series 9, 15, 21, ?, 33, 39

(a) 38 (b) 30

(e) None of these

Ans. (d)

Missing number = 21 + 6 = 27.

2. Which is the number that should come next in the following series?

3, 4, 6, 9, 13, ?

(a) 20

(b) 19

(d) 17

(e) None of these

Ans. (c)

Explanation:

Missing number = 13 + 5 = 18

3. Which number would replace the question mark (?) in the series

0, 1, 5, 14, 30, ?, 91

(a) 65

(b) 55

(d) 35

(e) None of these

Ans. (b)

Explanation:

4. Which is the number that should come next in the following series?

3, 7, 23, 59, ___.

(a) 123 (b) 112

(e) None of these

Ans. (a)

Explanation:

Commonly Asked Questions

Commonly Asked Questions

1. Which is the number that should come next in the following series?

0, 1, 10, 35, 84, ___.

(a) 175 (b) 165

(e) None of these

Ans. (b)

Explanation:

2. Which is the number that should come next in the following series?

6, 7, 15, 42, ___.

(a) 120 (b) 116

(e) None of these

Ans. (c)

Explanation:

3. Which number would replace the question mark (?) in the series \[\mathbf{64},\text{ }\mathbf{57},\text{ }\mathbf{50},\text{ }\mathbf{43},\text{ },\text{ }\mathbf{29}\]

(a) 30

(b) 36

(d) 22

(e) None of these

Ans. (b)

Explanation:

4. Which number would replace the question mark (?) in the series \[\mathbf{64},\text{ }\mathbf{63},\text{ }\mathbf{61},\text{ }\mathbf{58},\text{ },\text{ }\mathbf{49}\]

(a) 45 (b) 54

(e) None of these

Ans. (b)

Explanation:

5. Which number would replace the question mark (?) in the series \[\mathbf{64},\text{ }\mathbf{55},\text{ }\mathbf{47},\text{ }\mathbf{40},\text{ }\mathbf{34},\text{ },\text{ }\mathbf{25}\]

(a) 33 (b) 30

(e) None of these

Ans. (c)

Explanation:

Type-2

Letter Series

Letter Series This type of question usually consists of a series of small letters which follow a certain pattern. However some letters are missing from the series. These missing letters are given in a proper sequence as one of the alternatives.

Properties of Letter Series

This is a basic fundamental knowledge of letter series.

· A letter series can be in forward order.

· A letter series can be in reverse or backward order.

· A letter series can be in random or jumbled order.

· A letter series must have more than one element.

· Letters can be repeated in a letter series.

· A single letter series can have more than one series.

· Example:

Direction: In each of the following series determine the order of the letters and select the one from the given options which will complete the given series.

B Y C X D W E?

(a) S (b) T

(e) None of these

Ans. (d)

Explanation: Option (d) is correct. There are two alternate series.

Series I: BCDE (natural order). Series II: YXWV (reverse order)

2. A D C G E?

(a) G (b) J

(e) None of these

Ans. (b)

Explanation: Option (b) is correct. There are two alternate series.

Series I: ACE (follows + 2 pattern), Series II: DGJ (follows +3 pattern)

Types of Problems

(a) Problems based on increasing order series

(b) Problems based on decreasing order series

Problems Based on Increasing Order Series

'In such series, letters coming later in the English alphabet placed after the letters coming earlier in the English alphabet. Such series is also known as forward order series. · Example: In the following questions, various terms of letter series are given with one term missing. Choose the missing term out of the given alternatives.

J L N P R T?

(a) S (b) U

(e) None of these

Ans. (c)

Explanation: Option (c) is correct. This series is formed by skipping on letter each time.

2. F I M P?

(a) V (b) Q

(e) None of these

Ans. (c)

Explanation: Option (c) is correct. This series is formed by following order.

Problems Based on Decreasing Order Series

In such series, letters coming later in the English alphabet placed before the letters coming earlier in the English alphabet. This series is also called reverse order / backward order series. ·

Example

U R O L I .....

Series pattern:

Clearly, every next letter takes place 3 letters backward.

· Example H F D B .... Series pattern: Every next letter takes place skipping one letter in reverse order.

Problems Based on a Series having Mixed Series

In this type of questions, a series of single, pairs or groups of letters or combinations of letter and numerals is given. The terms of the series form a certain pattern as regards the position of the letters in the English alphabet. The candidate is required to decipher this pattern and accordingly find the missing term or the wrong term in the given series.

· Example

Which term comes next in the sequence given below?

AC, FH, KM, PR,?

(a) UW (b) VW

(e) None of these

Ans. (a)

Explanation: Option (a) is correct. Clearly the first and second letters of each term are moved five steps forward to obtain the corresponding letters of the next term. Thus, the first letter of the missing term must be five steps ahead of P i.e. U, while the second letter must be five steps ahead of R i.e. W. So, the missing term is UW. Hence, the answer is (a).

2. Find the next term in the series: BMO, EOQ, HQS,?

(a) KSU (b) LMN

(e) None of these

Ans. (a)

Explanation: Option (a) is correct.

Clearly, we observe the following pattern:

The first letters follow the pattern + 3i.e

The second letters follow the pattern + 2i.e.

The third letters follow the pattern + 2 i.e.

Thus, the missing term is KSU. Hence, the answer is (a).

Cyclic Order Series

This type of question usually consists of a series of small letters which follow a certain pattern. However some letters are missing from the series.

These missing letters are then given in a proper sequence as one of the alternatives. The candidate is required to choose this alternative as the answer. ·

Example

aab - aaa - bba-

(1) bba (2) abb (3) bab (4) aab (5) bbb

1. The first blank space should be filled in by V so that we have two a's followed by two bs.

2. The second blank space should be filed in either by 'a'. So that we have four as followed by two bs or by 'b'. So that we have three as followed by three bs.

3. The last space must be filled in by'a'.

4. Thus we have two possible answers- 'baa' and 'bba'. But only 'baa' appears in the alternatives. So the answer is (1).

5. In case we had both the possible answers in the alternatives, we should choose the one that forms a more prominent pattern, which is aabb/aaabbb/aa. and our answer would have been 'bba'.

Commonly Asked Questions?

Directions: In each of the following letter series, some of the letters are missing which are given in that order as one of the alternatives below it. Choose the correct alternative.

1. ba-ba - bac - acb - cbac

(a) aacb (b) bbca

(e) None of these

Ans. (c)

Explanation: Option (c) is correct. The series is bac/bac/bac/bac/bac/bac. Thus the pattern bac is repeated.

2. adb - ac - da - cddcb - dbc - cbda

(a) bccba (b) cbbaa

(e) None of these

Ans. (b)

Explanation: Option (b) is correct.

The series is adbcacbdabcddcbadbcacbda. Here the letters equidistant from the beginning and the end of the series are the same.

Type - 3

Mined Series

A mixed series comprises letters, numbers and symbols and unlike the English alphabet series the number of terms is not fixed in such series.

The questions on mixed series can be divided into two major heads:

(I) Series of letters and numbers

(II) Series of letters, numbers and symbols

Some Important Tips for (I)

· First of all, count the terms of the given series.

· Pin-point the middle term, if any.

· Write down the total number of letters, numbers and symbols respectively.

· Form the groups of five terms, count from either end so that you can recognise the position of the required term quickly.

· Example:

Direction: Read the following letter - number sequence and answer the questions given below:

S H M 9 B W F Q 7 N J 4 V A E T X 8 5 G K P Z R 3 I L

1. Which letter/number is fourth to the left of the 16th letter/number from your left?

(a) A (b) G

(e) None of these

Ans. (c)

Explanation:

[Short trick method] (16 - 4 = 12th from left)

2. If every alternate letter/number starting from 9 is dropped form the above sequence how many letters and numbers respectively will remain in the above sequence?

(a) 6 and 9 (b) 5 and 10

(e) None of these

Ans. (c)

Explanation: Remaining letters/number
S H M B F 7 J V E X 5 K Z 3 L

Letters = S, H, M, B, F, J, V, E, X, K, Z, L = Total = 12

Numbers = 7, 5, 3 = Total = 3

(II) Series of Letters, Numbers and Symbols

In order to make series more complicated, letters and numbers are combined with different symbols. Consider the following examples:

· Example:

Study the following letter - number symbol sequence carefully and answer the questions given below:

B D 5 F E 3 8 M2 8 K * P T @ U 9 A 7_\[\xi \]H J 4 Q 6

i. What should come in place of the question mark (?) in the following sequence? 5EA, MIP,?, IHQ

(a) TUA (b) TU7

(e) None of these

ii. Which of the following is the sixth to the right of the twentieth from the right end?

(a) K (b) P

(e) None of these

iii. Which of the following is exactly in the midway between the eleventh from the left end and the 7th from the right end?

(a) U (b) T

(e) None of these

iv. How many such digits are there in the above sequence which are immediately preceded as well as followed by digits?

(a) One (b) Two

(e) None of these

v. How many such consonants are there in the above sequence which are immediately preceded by a symbol and immediately followed by a digit?

(a) One (b) Two

(e) None of these

vi. If the first fifteen elements are written in the reverse order then which of the following will be eighth to the left of the thirteenth element from right end?

(a) M (b) 8

(e) None of these

Explanation:

· There are altogether 27 elements in the above sequence.

· There are only 14 letters in the above sequence.

· There are only 9 digits in the above sequence.

· There are only 4 symbols in the above sequence.

· The middle term of the sequence is P.

(i) Answer B is correct.

(ii) Answer B is correct. 6th to the right of 20th from the right means: 20 - 6 = 14th from the right end. There are altogether 27 elements in the above sequence and the middle term is 14th element from either end is R

(iii) Answer C is correct. 11th from left end = I

7th from right end = 1

Remaining elements between I and 1:

(iv) Answer E is correct. There is no such combination.

(v) Answer B is correct.

Symbol

Consonant

Digit

Such combination is M 2

Therefore, our required answer is option (b)

(vi) Answers A is correct. 8th to the left of 13th element from right end means 13 + 8 = 21st from the right end. 21st element from the right end is equivalent to 28 - 21 = 7th element from the left and vice - versa.

Thus,

\[{{1}^{st}},{{15}^{th}},{{2}^{nd}}\Leftrightarrow

{{14}^{th}},{{3}^{rd}}\Leftrightarrow {{13}^{th}}\]

\[{{9}^{th}}\Leftrightarrow {{12}^{th}},{{5}^{th}}\Leftrightarrow {{11}^{th}}\]

\[{{6}^{th}}\Leftrightarrow {{10}^{th}},{{7}^{th}}\Leftrightarrow {{9}^{th}}\]

Therefore, required element would be 9th from the 9th from left \[\to \](M)

Commonly Asked Questions

Direction: In each of the following questions a number series is given. A number in the series is suppressed by letter W. You have to find out the number in the place of W and use this number to find out the value in the place of the question mark in the equation following.

1. 42, 62, 93, 132, A, 242, 312 \[\mathbf{A+14=?\times 14}\]

(a) \[11\frac{6}{7}\] (b) \[14\]

(e) None of these

Ans. (b)

Explanation:

So \[=132+50=182\]

Then find the value of \[A+14=\times 14\]f

\[\Rightarrow \]\[182+14=\times 14\]

\[\Rightarrow \]\[196=\times 14\]

\[\Rightarrow \]\[=\frac{196}{14}=14\]

\[\Rightarrow \]\[=14\]

2. 4, 7, 12, 19, 28, A, 52

\[{{\mathbf{A}}^{\mathbf{2}}}\mathbf{-4=?}\]

(a) 1365 (b) 1353

(e) None of these

Ans. (c)

Explanation:

In a given series, adding to continuous odd number.

\[=28+11=\]

And \[{{A}^{2}}-4={{\left( 39 \right)}^{2}}-4=1521-4=1517\]

11th Class Mental Ability Series Notes - Series

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Notes - Series