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 series
EJO, 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