1.Find the missing term :- 2, 3, 3, 5, 10, 13, ?, 43, 172, 177

a) 23

b) 38

c) 39

d) 40

Explanation: The pattern is + 1, × 1, + 2, × 2, + 3, × 3, + 4, × 4, + 5

So, missing term = 13 × 3 = 39

2. Find the missing term: 563, 647, 479, 815, ?

a) 672

b) 386

c) 279

d) 143

Explanation: The pattern is + 84, - 168, + 336, .....i.e., + 84, - (84 × 2), + (84 × 2

^{2}),.................

So, missing term = 815 - (84 × 2

^{3}) = 815 - 672 = 143

3. Find the missing term, 4, 9, 25, ?, 121, 169, 289, 361

a) 49

b) 64

c) 81

d) 87

Explanation: The given series consists of squares of consecutive prime numbers i.e., 2

^{2}, 3

^{2}, 5

^{2},.....................,11

^{2}, 13

^{2}, 17

^{2}, 19

^{2}

So, missing term = 7

^{2}= 49

4. Find the missing term :- 240, ?, 120, 40, 10, 2

a) 180

b) 240

c) 420

d) 480

Explanation: The pattern is ÷ 1, ÷ 2, ÷ 3, ÷ 4, ÷ 5

So, missing term = 240 ÷ 1 = 240

5. Find the missing term :- 1, 9, 25, 49, 81, ?

a) 100

b) 112

c) 121

d) 144

Explanation: The series consists of squares of consecutive odd numbers i.e., 1

^{2}, 3

^{2}, 5

^{2}, 7

^{2}, 9

^{2},..............

So, missing term = 11

^{2}= 121

6. Find out the wrong term: 5, 27, 61, 122, 213, 340, 509

a) 27

b) 61

c) 122

d) 509

Explanation: The terms of the series are (2

^{3}- 3), (3

^{3}- 3), (4

^{3}- 3), (5

^{3}- 3), (6

^{3}- 3), (7

^{3}-3), (8

^{3}-3).

So, 27 is wrong and must be replaced (3

^{3}- 3) i.e., 24

7. Find out the wrong term: 6, 15, 35, 77, 165, 221

a) 35

b) 77

c) 165

d) 221

Explanation: The terms of the series are product of two consecutive prime numbers i.e., (2 × 3), (3 × 5), (5 × 7), (7 × 11),...........

So, 165 is wrong and must be replaced by (11 × 13) i.e., 143.

8. Find out the wrong term: 121, 143, 165, 186, 209

a) 143

b) 165

c) 186

d) 209

Explanation: Each term in the series is obtained by adding 22 to the preceding term.

So, 186 is wrong and must be replaced by (165 + 22) i.e., 187.

9. Find out the wrong term: 24576, 6144, 1536, 386, 96, 24

a) 96

b) 386

c) 1536

d) 6144

Explanation: Each term of the series is obtained by dividing the preceding term by 4.

So, 1536 is wrong and must be replaced by (1536 ÷ 4) i.e., 384.

10. Find out the wrong term: 16, 22, 30, 45, 52, 66

a) 30

b) 45

c) 52

d) 66

Explanation: The correct pattern is + 6, + 8, + 10, + 12, + 14.

So, 45 is wrong and must be replaced by (30 + 10) i.e., 40.