Question
Download Solution PDFFind the sum of the series 5 + 55 + 555 + ..... upto n terms ?
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFCONCEPT:
Let us suppose a be the first term and r be the common ratio of a GP. Then the general term of a GP is given by:
The sum of n terms of a GP with first term ‘a’ and common ratio ‘r’ is given by:
CALCULATION:
Here, we have to find the sum of the series 5 + 55 + 555 + ..... upto n terms
i.e 5 + 55 + 555 + ...... to n terms
= 5 ⋅ [1 + 11 + 111 + ..... to n terms]
=
=
=
As we know that,
=
=
Hence, the required sum is
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