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Home Verbal Reasoning Series Completion Comments

  • Question
  • Which term of the series 5, 10, 20, 40, ..... is 1280?


  • Options
  • A. 10th
  • B. 9th
  • C. 8th
  • D. None of these

  • Correct Answer
  • 9th 

    Explanation
    Clearly, 5 x 2 = 10, 10 x 2 = 20, 20 x 2 = 40,.....

    So, the series is a G.P. in which a = 5 and r = 2.

    Let 1280 be the rath term of the series.

    Then, 5x2n-1 = 1280 ⟺ 2n-1 = 256 = 28 ⟺ n - 1 = 8 ⟺ n = 9.


    Series Completion problems


    Search Results


    • 1. 6, 12, 21,?, 48

    • Options
    • A. 33
    • B. 38
    • C. 40
    • D. 45
    • Discuss
    • 2. 2, 3, 5,7,11,?, 17

    • Options
    • A. 12
    • B. 13
    • C. 14
    • D. 15
    • Discuss
    • 3. 198, 194, 185, 169,?

    • Options
    • A. 92
    • B. 112
    • C. 136
    • D. 144
    • Discuss
    • 4. 3, 4, 7, 7, 13, 13, 21, 22, 31, 34,?

    • Options
    • A. 42
    • B. 43
    • C. 51
    • D. 52
    • Discuss
    • 5. 1, 3, 4, 8, 15, 27,?

    • Options
    • A. 37
    • B. 44
    • C. 50
    • D. 55
    • Discuss
    • 6. 2, 5, 9,?, 20, 27

    • Options
    • A. 14
    • B. 16
    • C. 18
    • D. 24
    • Discuss
    • 7. 2, 3, 3, 5, 10, 13,?, 43, 172, 177

    • Options
    • A. 23
    • B. 38
    • C. 39
    • D. 40
    • Discuss
    • 8. 9, 27, 31, 155, 161, 1127,?

    • Options
    • A. 316
    • B. 1135
    • C. 1288
    • D. 2254
    • Discuss
    • 9. 2, 1, 2, 4, 4, 5, 6, 7, 8, 8, 10, 11,?

    • Options
    • A. 9
    • B. 10
    • C. 11
    • D. 12
    • Discuss
    • 10. Which of the following will not be a number of the series 1, 8, 27, 64, 125,.....?

    • Options
    • A. 256
    • B. 512
    • C. 729
    • D. 1000
    • Discuss


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