Sequences and Series


Direction: What should come in place of the question mark in each of the following number series ?

  1. 6, 13, 32, ?, 130, 221.









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    Series pattern
    13 + 5, 23 + 5, 33 + 5, 43 + 5, 53 + 5

    Correct Option: B

    Series pattern
    13 + 5, 23 + 5, 33 + 5, 43 + 5, 53 + 5
    ∴ Missing term = 43 + 5 = 69


  1. 656, 432, 320, 264, 236, ?









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    Series pattern
    656 - 224 = 432
    432 - 112 = 320
    320 - 56 = 264 .....

    Correct Option: A

    Series pattern
    656 - 224 = 432
    432 - 112 = 320
    320 - 56 = 264
    264 - 28 = 236
    236 - 14 = 222 Should come in place of '?'



  1. 16, 4, 2, 1.5, 1.75, 1.875









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    Series pattern
    16 x 0.25 = 4,
    4 x 0.50 = 2,
    2 x 0.75 =1.5,
    1.5 x 1.00 = 1.5

    Correct Option: B

    Series pattern
    16 x 0.25 = 4,
    4 x 0.50 = 2,
    2 x 0.75 =1.5,
    1.5 x 1.00 = 1.5
    Should come in place of 1.75
    1.5 x 1.25 = 1.875
    Clearly, 1.75 is wrong and will be replaced by 1.5


  1. 7, 9, 16, 25, 41, 68, 107, 173, ?









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    Series pattern
    7 + 9 = 16,
    9 + 16 = 25,
    16 + 25 = 41,
    25 + 41 = 66
    Should come in place of 68

    Correct Option: D

    Series pattern
    7 + 9 = 16,
    9 + 16 = 25,
    16 + 25 = 41,
    25 + 41 = 66
    Should come in place of 68
    41 + 66 = 107,
    66 + 107 = 173
    Clearly, 68 is wrong and will be replaced by 66.



  1. 2, 6, 14, 30, .... 126, ?









  1. View Hint View Answer Discuss in Forum

    Series pattern = (2 x Previous number) + 2

    Correct Option: A

    Series pattern = (2 x Previous number) + 2
    ∴ Missing term = 2 x 30 +2 = 62