Sequences and Series


  1. Find out the next term in the series 7, 11, 13, 17, 19, ...









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    Given series is a consecutive prime number series.

    Correct Option: B

    Given series is a consecutive prime number series. Therefore, the next term will be 23.


  1. Find the missing term 6, ?, 21, 33, 48









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    Series Pattern
    +6, +9, +12, +15...

    Correct Option: C

    Series Pattern
    +6, +9, +12, +15....
    ∴ Missing term = 6 + 6 = 12



  1. Find the value of the expression 1 - 2 + 3 - 4 + 5 - 6 + 7 + .... upto 100 terms . ?









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    (1 - 2) = -1
    (3 - 4) = -1
    (5 - 6) = -1

    Correct Option: D

    (1 - 2) = -1
    (3 - 4) = -1
    (5 - 6) = -1
    and so on.
    ∴ Total terms of -1 will be 50.
    ∴ Answer = -1 x 50 = -50


  1. If A represents the arithmetic mean, H represents the harmonic mean and G represents the geometric mean, then what is the relation between them ?









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    A = (a + b)/2,
    1/H = (1/a + 1/b)/2
    ⇒ H = 2ab/(a +b),
    G = √ab

    Correct Option: B

    A = (a + b)/2,
    1/H = (1/a + 1/b)/2
    ⇒ H = 2ab/(a +b),
    G = √ab
    ∴ A x H = {(a + b)/2} x {2ab/(a + b)} = ab = G2
    ∴ A x H = G2



  1. 4, 12, 36, ?, 324, 972









  1. View Hint View Answer Discuss in Forum

    Series pattern
    Every next element = 3 x previous element

    Correct Option: A

    Series pattern
    Every next element = 3 x previous element
    ∴ Missing term = 3 x 36 = 108