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JEE Main20207 Jan 2020Morning ShiftMathematicsSequences and SeriesActual

The greatest positive integer k , for which 49 k + 1 is a factor of the sum 49 125 + 49 124 + … + 49 2 + 49 + 1 , is

Options

  1. A32
  2. B63
  3. C60
  4. D35

Correct answer

B. 63

Step-by-step solution

This series is a G.P. with first term 49 125 and common ratio 1 49 . So, its sum = 49 126 - 1 48 = 49 63 + 1 49 63 - 1 48

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