Direction: In the following number series, a wrong number is given. Find out that wrong number.
1. 160 80 120 180 1050 4725 25987.5
A. 60
B. 90
C. 3564
D. 87.5
E. 135
2. 2 10 18 54 162 486 1458
A. 18
B. 54
C. 162
D. 10
E. None of these
3. 214 18 162 62 143 90 106
A. -34
B. 110
C. 10
D. 91
E. 38
4. 250 239 216 181 136 75 4
A. 239
B. 181
C. 75
D. 216
E. 136
5. 3 4 10 34 136 685 4116
A. 22
B. 276
C. 72
D. 374
E. 12
Direction: In the following number series, a wrong number is given. Find out that wrong number.
6. 3 5 12 38 154 914 4634
A. 1632
B. 1222
C. 1834
D. 3312
E. 1488
7. 4 2.5 3.5 6.5 15.5 41.25 126.75
A. 2.5
B. 3.5
C. 6.5
D. 15.5
E. 41.25
8. 4 6 18 49 201 1011
A. 1011
B. 201
C. 18
D. 49
E. None of these
9. 484 240 120 57 26.5 11.25 3.625
A. 240
B. 120
C. 57
D. 26.5
E. None of these
10. 5 348 564 689 716 780 788
A. 716
B. 788
C. 348
D. 689
E. 780
Answers and Explanations
1. Answer - Option E
Explanation -
The series is based on following pattern:
160 × 0.5 = 80
80 × 1.5 = 120
120 × 2.5 = [300]
300 × 3.5 = 1050
1050 × 4.5 = 4725
4725 × 5.5 = 25947.5
Therefore, the number 180 is wrong.
i.e, According to the question, the new series starts from the number 180 in the same pattern:
180 × 0.5 = 90
90 × 1.5 = [135]
Hence, the number 135 is required answer.
2. Answer - Option D
Explanation -
The pattern is:
2 × 3 = 6 [latex]\neq[/latex] [10]
6 × 3 = 18
18 × 3 = 54
54 × 3 = 162
3. Answer - Option D
Explanation -
The series is based on following pattern:
214 – [latex]{(14)}^{2}[/latex] = 18
18 + [latex]{(12)}^{2}[/latex] = 162
162 – [latex]{(10)}^{2}[/latex] = 62
62 + [latex]{(8)}^{2}[/latex] = [126]
126 – [latex]{(6)}^{2}[/latex] = 90
90 + [latex]{(4)}^{2}[/latex] = 106
Therefore, the number 143 is wrong.
i.e, According to the question, the new series starts from the 143 in the same pattern.
143 – [latex]{(14)}^{2}[/latex] = – 53
– 53 + [latex]{(12)}^{2}[/latex] = [91]
Hence, the number 91 is required answer.
4. Answer - Option E
Explanation -
The pattern is :
250 – 11 = 239
239 – (11× 2 + 1) = 239 – 23 = 216
216 – (11 × 3 + 2) = 216 – 35 = 181
181 – (11 × 4 + 3) = 181 – 47 = 134 [latex]\neq[/latex] [136]
134 – (11 × 5 + 4) = 134 – 59 = 75
75 – (11 × 6 + 5) = 75 – 71 = 4
5. Answer - Option C
Explanation -
The series is based on following pattern:
3 × 1 + 1 = 4
4 × 2 + 2 = 10
10 × 3 + 3 = [33]
33 × 4 + 4 = 136
136 × 5 + 5 = 685
685 × 6 + 6 = 4116
Therefore, the number 34 is wrong.
i.e, According to question, the new series starts from numbers 34 in the same pattern
34 × 1 + 1 = 35
35 × 2 + 2 = [72]
Hence, the number 72 is required answer.
6. Answer - Option C
Explanation -
The series is based on following pattern:
3 × 1 + 2 = 5
5 × 2 + 2 = 12
13 × 3 + 2 = 38
38 × 4 + 2 = 154
154 × 5 + 2 = [772]
772 × 6 + 2 = 4634
Therefore, the number 914 is wrong.
i.e, According to question, the new series is as follows:
914 × 1 + 2 = 916
916 × 2 + 2 = [1834]
1834 × 3 + 2 = 5504
Therefore the required number is 1834
7. Answer - Option C
Explanation -
The pattern of the number series is:
4 × 0.5 + 0.5 = 2 + 0.5 = 2.5
2.5 × 1 + 1 = 3.5
3.5 × 1.5 + 1.5 = 6.75 [latex]\neq[/latex][6.5]
6.75 × 2 + 2 = 15.5
15.5 × 2.5 + 2.5 =38.75 + 2.5 = 41.25
41.25 × 3 + 3 = 123.75 + 3 = 126.75
8. Answer - Option C
Explanation -
4 × 1 + 2 = 4 + 2 = 6
4 × 2 + 3 = 12 + 3 = 15 [latex]\neq[/latex] 18
15 × 3 + 4 = 45 + 4 = 49
49 × 4 + 5 = 196 + 5 = 201
201 × 5 + 6 = 1005 + 6 = 1011
9. Answer - Option B
Explanation -
The pattern of the number series is:
([latex]\frac{484}{2}[/latex]) – 2 = 242 – 2 = 240
([latex]\frac{440}{2}[/latex]) – 2 = 120 – 2 = 118 [latex]\neq[/latex] [120]
([latex]\frac{118}{2}[/latex]) – 2 = 59 – 2 = 57
([latex]\frac{57}{2}[/latex]) -2 = 28.5 – 2 = 26.5
10. Answer - Option A
Explanation -
The pattern of the number series is:
5 + [latex]{7}^{3}[/latex] = 5 + 343 =348
348 + [latex]{6}^{3}[/latex] =348 + 216 =564
564 + [latex]{5}^{3}[/latex] = 564 + 125 = 689
689 + [latex]{4}^{3}[/latex] = 689 + 64 = 753, [latex]\neq[/latex] [716]
753 + [latex]{3}^{3}[/latex] = 753 + 27 = 780