Arithmetic and Geometric Progressions

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Sequence and Series

Sum of Series

    Find the sum of the series .4 + .44 + .444……. to n terms
    1. 5.69
    2. 14.44

 

  • Correct Answer
    Choice C.

Detailed Solution

.4 + .44 + .444+……. to n terms

= 4x[0.1 +0.11 +0.111+……..to n terms]

= * [0.9 +0.99 + 0.999+…….to n terms] (Multiplying and dividing by 9)

= * [(1-0.1)+(1-0.01)+(1-0.001)+…….to n terms]

= * [(1+1+1…..to n terms)-(0.1+0.01+0.001…to n terms)]

=

=

=

=

=

Correct Answer:



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More questions from Progressions

  1. Counting and Progressions
  2. Common Ratio
  3. Common Difference
  4. Sum up to 'n' Terms
  5. AP Puzzle
  6. GP Logical Puzzle
With some simple but very powerful ideas, one can cut down on a lot of working when it comes to progressions. For example, anchoring a progression around its middle term can be very useful. Reinforce these ideas with these questions.