### NTSE Mental Ability Test (MAT) Questions Based on Series

#### Number Series

In this type of series, the set of given numbers in a series are related to one another in a particular pattern or manner. The relationship between the numbers may be

(i) consecutive odd/even numbers,

(ii) Consecutive prime numbers,

(iii) Squares/cubes of some numbers with/without variation of addition or subtraction of some number,

(iv) Sum/product/difference of preceding number(s),

(v) Addition/subtraction/multiplication/division by some number, and

(vi) Many more combinations of the relationships given above.

*Example: *

Complete the given series 4, 9, 13, 22, 35……….

(1) 57

(2) 70

(3) 63

(4) 75

**Answer: **(1) 4 + 9 = 13, 13 + 9 = 22 etc.

*Example: *

Complete the given series 66, 36, 18, ……….

(1) 9

(2) 3

(3) 6

(4) 8

**Answer: **(4) 6 × 6 = 36; 3 × 6 = 18; 1 × 8 = 8.

*Example: *

Complete the given series 61, 67, 71, 73, 79, ……….

(1) 81

(2) 82

(3) 83

(4) 85

**Answer: **(3) Prime number series. 83 is the next prime number.

#### Alphabet Series

In this type of question, a series of single, pairs or groups of letters or combinations of letters and numbers is given. The terms of the series form a certain pattern as regards the position of the letters in the English alphabet.

** Directions:** In the following questions, various terms of a letter series are given with one term missing as shown. Choose the missing term out of the options.

*Example: *

A, B, B, D, C, F, D, H, E, ?, ?

(1) E, F

(2) F, G

(3) F, I

(4) J, F

**Answer: **(4) The given sequence is a combination of two series :

I. 1st, 3rd, 5th, 7th, 9th, 11th terms i.e. A, B, C, D, E ?

II. 2nd, 4th, 6th, 8th, 10th terms i.e. B, D, F, H ?

Clearly, I consists of consecutive letters while II consists of alternate letters. So, the missing letter in I is F, while that in II is J.

So, the missing terms i.e. 10th and 11th terms are J and F respectively.

#### Alpha – Numeric Series:

A series in which both alphabets and numbers are used is called Alpha numeric.

**Directions: **In each of the following questions, a letter number series is given with one or more terms missing as shown by (?). Choose the missing term out of the given alternatives.

*Example: *

D-4, F-6, H-8, J-10, ? ?

(1) K-12, M-13

(2) L-12, M-14

(3) L-12, N-14

(4) K-12, M-14

Answer: (3) The letters in the series are alternate and the numbers indicate their position in the English alphabet from the beginning.

*Example: *

Find the missing term.

2 Z 5, 7 Y 7, 14 X 9, 23 W 11, 34 V 13, ?

**Answer: **First number is the sum of the numbers of the preceeding term.

Middle letter is moved one step backward.

Third number is a series of odd numbers.

Therefore, 6th term = 47 U 15.

#### Questions For Practice:

**Directions (Q.1-11) : **In each of the following questions, a sequence or groups of letters and numbers is given with one term missing as shown by (?). Choose the missing term out of the given alternatives.

**Q.1. 1, 2, 10, 4, 3, 14, 9, 5, …….**

(1) 19

(2) 20

(3) 17

(4) 18

## Answer

Answer: (4)**Q.2. Find the missing term in the seriesEJO, TYD, INS, XCH, ?**

(1) NRW

(2) MRW

(3) MSX

(4) NSX

## Answer

Answer: (2) There is a gap of four letters between first and second, second and third letter of each term. Also there is a gap of 4 letters between the last letter of a term and the first letter of the next term.**Q.3. Find out the missing number.240, ? 120, 40, 10, 2 –**

(1) 120

(2) 240

(3) 40

(4) 10

## Answer

Answer: (2)**Q.4. J2Z, K4X, I7V, ?, H16R, M22P**

(1) I11T

(2) L11S

(3) L12T

(4) L11T

## Answer

Answer: (4) The first letters in odd numbered terms from the series J, I, H and in even numbered terms from the series K, L, M.The sequence followed by the numbers is +2, +3, +4, +5, +6. The third letter of each term is moved two steps backward to obtain the third letter of the next term.

**Q.5. B Y C X D W E ?**

(1) S

(2) T

(3) U

(4) V

## Answer

Answer: (4)**Q.6. 3, 8, 35, 48, ?, 120**

(1) 64

(2) 72

(3) 80

(4) 99

## Answer

Answer: (4)**Q.7. B D G K ? V**

(1) N

(2) P

(3) Q

(4) M

## Answer

Answer: (2)**Q.8. B C D B D D B E D B F D B G ?**

(1) B D

(2) B F

(3) H B

(4) D B

## Answer

Answer: (4)**Q.9. A D E H I L M P Q T U ?**

(1) X Y

(2) Y Z

(3) U V

(4) V W

## Answer

Answer: (1)**Q.10. 3, 6, 18, 72, 360, …..**

(1) 1296

(2) 2160

(3) 2254

(4) 4329

## Answer

Answer: (2) The first number 3 is multiplied by 2 to get next number 6. The successive numbers are multiplied by 3, 4, 5, 6 etc.Hence the number next to 360 × 6 = 2160.

**Q.11. 5, 9, 21, 37, 81, …….**

(1) 153

(2) 150

(3) 158

(4) 151