## Number Series Sample Questions:

Ready for some hands-on practice? Great.

My advice is that you go slow through the sample questions below and the answer breakdown that follows each one.

The objective of this section is to help you learn some solving tips and techniques in an active and memorable way, not to simulate your test conditions.

Let’s delve deep into numerical reasoning number series questions, so you could crush them on your coming assessment.

In each series, look for the degree and direction of change between the numbers. In other words, do the numbers increase or decrease, and by how much.

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1. 32 31 32 29 32 27 32 ? ? A. 25 ,32 B. 31, 32 C. 29, 32 D. 25 ,30 Answer: Option A Explanation: This is an alternating repetition series. The number 32 alternates with a series in which each number decreases by 2. |

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2. 10 34 12 31 14 28 16 ? ? A. 25 , 18 B. 30, 13 C. 19 ,26 D. 18 ,20 Answer: Option A Explanation: Two patterns alternate here. The first pattern begins with 10 and adds 2 to each number to arrive at the next; the alternating pattern begins with 34 and subtracts 3 each time. |

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3. 34 30 26 22 18 14 10 ? ? A. 8, 6 B. 6, 4 C. 14, 18 D. 6, 2 Answer: Option D Explanation: This is a simple subtraction series, in which 4 is subtracted from each number to arrive at the next. |

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4. 2 44 4 41 6 38 8 ? ? A. 10, 12 B. 35, 32 C. 34, 9 D. 35 ,10 Answer: Option D Explanation: Here, there are two alternating patterns, one addition and one subtraction. The first starts with 2 and increases by 2; the second starts with 44 and decreases by 3. |

1 2 3 4 5 6 7 8 9 10 11 12 |
5. 17 16 14 12 11 8 8 ? 1. 4 2. 7 3. 3 4. 2 Answer: Option 1 Explanation: There are two series: 1st : 17 14 11 8 and 2nd: 16 12 8 ? In 1st series: -3 , -3 ,-3….. and in 2nd series: -4 , -4 ,-4…. Therefore, next term will be 8 – 4 = 4. |

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6. 9 16 23 30 37 44 51 ? ? A. 59 ,66 B. 56, 62 C. 58 ,66 D. 58, 65 Answer: Option D Explanation: Here is a simple addition series, which begins with 9 and adds 7. |

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7. 17, 19, 23, 29, 31, 37, __ A. 47 B. 43 C. 40 D. 41 Answer: Option D Explanation: The given numbers are consecutive prime numbers in increasing order starting with 17. Hence, the next number in the series is 41. |

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8. 54, 66, 82, 102, 126, __ A. 146 B. 130 C. 154 D. 144 Answer: Option C Explanation: 54+12, 66+18, 82+20, 102+24, 126, __. The difference is increasing by 4, starting with 12. So, the next difference is 24 + 4 = 28. Hence, the next number is 126 + 28 = 154. |

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9.3 2 2 5 5 5 7 8 8 9 11 11 ? 1. 12 2. 11 3. 9 4. 14 Answer: Option 2 Explanation: There are three parallel series going on in this question. The 1st, 4th, 7th terms are using logic of -1, 2nd, 5th and 8th terms are using logic of +1 and 3rd, 6th and 9th terms are using logic of +1 again. Answer will be 11, which belongs to 1st, 4th and 7th term. |

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10. 1 3 2 6 3 11 4 18 5 ? 1. 27 2. 25 3. 23 4. 29 Answer: Option 1 Explanation: There are three parallel series going on in this question. Starting from 1st element 1+1=2 is placed at 3rd position, 2+1=3 and so on. Another starting point at 2nd position 3+3=6 is placed at 4th position and 6+5=11 so on. |

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11. 13 17 23 29 31 37 ? 1. 22 2. 41 3. 19 4. 23 Answer: Option 2 Explanation: The given series is a prime number series. Hence the next prime number in this sequence would be 41. |

## Find the wrong no. in this series

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Find the wrong no. in this series 12. 2 3 10 38 172 1. 192 2. 10 3. 38 4. 2 Answer: Option 3 Explanation: Logic is 2×1 + 1 = 3, 3 × 2 + 4 =10, 10 × 3 + 9 = 39, 39 × 4 + 16 = 172…. So in place of 38, it should be 39. |

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Find the wrong no. in this series 13. 8 19 52 151 447 1. 19 2. 8 3. 52 4. 447 Answer: Option 4 Explanation: The logic is 8 × 3 – 5 = 19, 19 × 3 – 5 = 52, 52 × 3 – 5 = 151. So in place of 447, it should be 448. |

1 2 3 4 5 6 7 8 |
Find the wrong no. in this series 14. 4 2 3 7.5 26.75 1. 26.75 2. 7.5 3. 3 4. 2 Answer: Option 1 Explanation: Logic is 4 × .5 = 2, 2 × 1.5 = 3, 3 × 2.5 = 7.5, 7.5 × 3.5 = 26.25 In place of 26.75, it should be 26.25. |

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Find the wrong no. in this series 15. 2 3 10 40 172 885 5346 1. 3 2. 885 3. 40 4. 172 Answer: Option 3 Explanation: Logic is 2 × 1 + 1 = 3, 3 × 2 + 4 = 10, 10 × 3 + 9 = 39. Thus the wrong number is 40,it should be 39. |

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Find the wrong no. in this series 16. 15 18 20 29 45 70 106 1.18 2.20 3.29 4.45 Answer: Option 1 Explanation: Starting from the back 106– 70 = 36, 70- 45 = 25, 45 – 29 = 16, 29 – 20 = 9, 20 – 16 = 4, 16 – 15 = 1. Every difference is perfect square starting from 36 and decreasing. Thus the wrong number is 18, it should be 16. |

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Find the wrong no. in this series 17. 11 14 20 29 40 56 1. 40 2. 4 3. 10 4. 19 Answer: Option 1 Explanation: Logic is that first difference is 3, next difference is 6, 9, so next should be 12 & 15. So instead of 40 the term should be 41. |

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Find the wrong no. in this series 18. 49 50 46 55 38 64 28 1. 49 2. 46 3. 55 4. 38 Answer: Option 4 Explanation: Logic is 49 + 1 = 50, 50 – 4 = 46, 46 + 9 = 55, 55 – 16 = 39, 39 + 25 = 64. Thus the wrong number is 38, it should be 39. |

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Find the wrong no. in this series 19. 6 15 41 179 839 1. 15 2. 6 3. 179 4. 41 Answer: Option 3 Explanation: Logic is 6 × 2 + 3 = 15, 15 × 3 – 4 = 41, 41 × 4 + 5 = 169, 169 × 5 – 6 = 839. Thus the wrong number is 179, it should be 169. |

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Find the wrong no. in this series 20. 4 6 12 30 90 312.50 1260 1. 6 2. 90 3. 30 4. 312.50 Answer: Option 4 Explanation: Logic is 4 × 1.5 = 6, 6 × 2 = 12, 12 × 2.5 = 30, 30 × 3 = 90, 90 × 3.5 = 315, 315 × 4 = 1260. Thus the wrong number is 312.50, it should be 315. |

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Find the wrong no. in this series 21. 35 19 11 7 5 4.5 3.5 1. 4.5 2. 5 3. 11 4. 19 Answer: Option 1 Explanation: 35-19 = 16, 19-11 = 8, 11-7 = 4, 7-5 = 2, 5-4 = 1, 4-3.5 = .5 The difference is halved every time. Thus the wrong number is 4.5, it should be 4. |

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