Practice Exercise 1: Find out the next term in place of question mark (?) in the following number series.

7 , 4.5 , 5.5 , 12 , 49 , ?

A. 393

B. 396

C. 354

D. 367

E. None of these

7 × 0.5 + 1 = 4.5

4.5 × 1 + 1 = 5.5

5.5 × 2 + 1 = 12

12 × 4 + 1 = 49

Following this pattern, the next term = 49 × 8 + 1 = 393

Therefore, A is the correct option.

Note: You should calculate 49 × 8 as 50 × 8 – 8 = 392

Practice Exercise 2: Find out the next term in place of question mark (?) in the following number series.

17 , 98 , 26 , 89 , 35 , (?)

A. 80

B. 75

C. 67

D. 53

E. None of these

Let’s check the difference between the consecutive terms.

98 – 17 = 81

26 – 98 = -72

89 – 26 = 63

35 – 89 = -54

Following this pattern, the next term = 45 + 35 = 80

So, A is the correct option.

Practice Exercise 3: What should come in place of question mark (?) in the following number series?

3240 , 540 , 108 , 27 , ? , 4.5

A. 7

B. 10

C. 9

D. 8

E. None of these

3240 ÷ 6 = 540

540 ÷ 5 = 108

108 ÷ 4 = 27

27 ÷ 3 = 9

9 ÷ 2 = 4.5

Therefore, the missing term is 9. So, C is the correct option.

Practice Exercise 4: Find out the next number in place of question mark (?) in the following number series.

3 , 5 , 15 , 45 , 113 , ?

A. 250

B. 243

C. 247

D. 261

E. None of these

5 = 3 + (13 + 1)

15 = 5 + (23 + 2)

45 = 15 + (33 + 3)

113 = 45 + (43 + 4)

Following this pattern, the next term = 113 + (53 + 5) = 243.

Therefore, B is the correct option.

Practice Exercise 5: Find out the next term in place of question mark (?) in the following number series.

305 , 338 , 404 , 503 , 635 , ?

A. 820

B. 880

C. 800

D. 890

E. 790

305 + 33 = 338

338 + 66 = 404

404 + 99 = 503

503 + 132 = 635

Following this pattern, the next term = 635 + 132 + 33 = 800.

Therefore, C is the correct option.

Practice Exercise 6: Find out the next term in place of question mark (?) in the following number series?

8 , 14 , 26 , 44 , 68 , ?

A. 94

B. 102

C. 96

D. 98

E. None of these

8 + 6 = 14

14 + 12 = 26

26 + 18 = 44

44 + 24 = 68

Following this pattern, the next term = 68 + 24 + 6 = 98

Therefore, D is the correct option.

Practice Exercise 7: Find out the next term in place of question mark (?) in the following number series?

11 , 19 , 40 , 87 , 173 , ?

A. 301

B. 311

C. 304

D. 294

E. 350

Solution: Practice Problem 8

Therefore, B is the correct option.

Practice Exercise 8: Find the next term in place of question mark (?) in the following number series.

14 , 18 , 9 , 25 , 0 , ?

A. 11

B. 23

C. 36

D. 20

E. 40

14 + 22 = 18

18 – 32 = 9

9 + 42 = 25

25 – 52 = 0

0 + 62 = 36

Therefore, the next term is 36. So, C is the correct option.