Quantitative Aptitude: Number Series For SBI PO/NIACL/NICL

Directions (1-5): In the following number series, a wrong number is given. Find out that wrong number.

Q1. 2 11 38 197 1172 8227 65806

(a) 11

(b) 38

(c) 197

(d) 1172

(e) 8227

Q2. 16 19 21 30 46 71 107

(a) 19

(b) 21

(c) 30

(d) 46

(e) 71

Q3. 7 9 16 25 41 68 107 173

(a) 107

(b) 16

(c) 41

(d) 68

(e) 25

Q4. 4 2 3.5 7.5 26.25 118.125

(a) 118.125

(b) 26.25

(c) 3.5

(d) 2

(e) 7.5

Q5. 16 4 2 1.5 1.75 1.875

(a) 1.875

(b) 1.75

(c) 1.5

(d) 2

(e) 4

Directions (6-10) : In each of the following questions a number series is given. After the series a number is given followed by (a), (b), (c), (d) and (e). You have to complete the series starting with the given number, following the sequence of original series and answer the questions that follow the series.

Q6. 3 19 103 439 1381 2887

5 (a) (b) (c) (d) (e)

What will come in place of (b) ?

(a) 139

(b) 163

(c) 161

(d) 157

(e) None of these

Q7. 4 13 40 135 552 2765

2 (a) (b) (c) (d) (e)

What will come in place of (c) ?

(a) 123

(b) 133

(c) 127

(d) 131

(e) None of these

Q8. 5 12 4 10 3 8

6 (a) (b) (c) (d) (e)

What will come in place of (d) ?

(a) 3

(b) 5

(c) 4

(d) 7

(e) None of these

Q9. 3 13 37 87 191 401

1 (a) (b) (c) (d) (e)

What will come in place of (d) ?

(a) 169

(b) 161

(c) 171

(d) 159

(e) None of these

Q10. 8 4 6 15 52.5 236.25

12 (a) (b) (c) (d) (e)

What will come in place of (c) ?

(a) 23.5

(b) 16.5

(c) 22.5

(d) 22.25

(e) None of these

Directions (11-15) : What should come in place of question mark (?) in the following number series ?

Q11. 13 14 30 93 376 1885 ?

(a) 10818

(b) 10316

(c) 11316

(d) 11318

(e) None of these

Q12. 4 6 9 13.5 20.25 30.375 ?

(a) 40.25

(b) 45.5625

(c) 42.7525

(d) 48.5625

(e) None of these

Q13. 400 240 144 86.4 51.84 31.104 ?

(a) 19.2466

(b) 17.2244

(c) 16.8824

(d) 18.6624

(e) None of these

Q14. 9 4.5 4.5 6.75 13.5 33.75 ?

(a) 101.25

(b) 103.75

(c) 99.75

(d) 105.50

(e) None of these

Q15. 705 728 774 843 935 1050 ?

(a) 1190

(b) 1180

(c) 1185

(d) 1187

(e) None of these

SOLUTION:

S1. Ans.(d)

Sol. The series is based on the following pattern:

11 = 2 × 3 + 5

38 = 11 × 4 - 6

197 = 38 × 5 + 7

1172 ≠ 197 × 6 - 8

1172 is wrong and it should be replaced by 197 × 6 - 8 = 1174

S2. Ans.(a)

Sol. The series is based on the following pattern:

107 - 71 = 36

71 - 46 = 25

46 - 30 = 16

30 - 21 = 9

21 - 19 = 2≠4

19 should be replaced by 17 for which 21 - 17 = 4

S3. Ans.(d)

Sol. The series is based on the following pattern:

16 = 9 + 7

25 = 16 + 9

41 = 25 + 16

68 ≠ 41 + 25

68 should be replaced by 66.

S4. Ans.(c)

Sol. The series is based on the following pattern: ×0.5,×1.5,×2.5,×3.5,×4.5

Obviously, 3.5 Is the wrong number which should be replaced by 3.

S5. Ans.(b)

Sol. The series is based on the following pattern: ×0.25,×0.5,×0.75,×1,×1.25

Obviously, 1.75 is the wrong number which should be replaced by 1.5.

S6. Ans.(b)

Sol. The given series is based on the following pattern : ×6+1,×5+8,×4+27,×3+64,×2+125

Similarly, 5×6+1=31

31×5+8=163

Hence, 163 will come in place of (b)

S7. Ans.(a)

Sol. The given series is based on the following pattern

13 = 4 × 1 + 1 × 9

40 = 13 × 2 + 2 × 7

135 = 40 × 3 + 3 × 5

552 = 135 × 4 + 4 × 3

2765 = 552 × 5 + 5 × 1

Similarly,

(a) = 2 × l + 1 × 9 = 11

(b) = 11 × 2 + 2 × 7 = 36

(c) = 36 × 3 + 3 × 5 = 123

Hence, 123 will come in place of (c).

S8. Ans.(c)

Sol. The given series is based on the following pattern: ×2+2,÷2-2,×2+2,÷2-2………..

Hence, 4 will come in place of (d).

S9. Ans.(d)

Sol. The given series is based on the following pattern : ×2+7,×2+11,×2+13,×2+17,×2+19

(7, 11, 13, 17, 19, ..... are consecutive prime numbers)

Hence, 159 will come in place of (d).

S10. Ans.(c)

Sol. The given series is based on the following pattern : ×0.5,×1.5,×2.5…….

Hence, 22.5 will come in place of (c).

S11. Ans.(c)

Sol. The given number series is based on the following pattern :

13 × 1 + 1 = 14

14 × 2 + 2 = 30

30 × 3 + 3 = 93

93 × 4 + 4 = 376

376 × 5 + 5 = 1885

? = 1885 × 6 + 6 = 11316

Hence, number 11316 will replace the question mark.

S12. Ans.(b))

Sol. The given series is based on the following pattern :×1.5,×1.5,……..

S13. Ans.(d)

Sol. The given series is based on the following pattern : ×0.6,×0.6……..

S14. Ans.(a)

Sol. The given series is based on the following pattern : ×0.5,×1,×1.5,×2,×2.5…….

S15. Ans.(e)

Sol.

705 + 1 × 23 = 728

728 + 2 × 23 = 774

774 + 3 × 23 = 843

843 + 4 × 23 = 935

935 + 5 × 23 = 1050

? = 1050 + 6 × 23 = 1050 + 138 = 1188

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