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Re: The sum of all the digits of 1/(5^5 * 2^9) when it is written in [#permalink]
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SaquibHGREWhiz wrote:
Quantity A
Quantity B
The sum of all the digits of \(\frac{1}{(5^5 × 2^9)}\) when it is written in decimal format
The sum of all the digits of \(\frac{1}{(5^6 ×2^{10})}\) when it is written in decimal format


A. Quantity A is greater
B. Quantity B is greater
C. The two quantities are equal
D. The relationship cannot be determined from the information given


Source: GREWhiz


For Quantity A:

Rewritting the expression:
\(\frac{1}{(5^5 \times 2^9)} = \frac{1}{(5^5 \times 2^5 \times 2^4)} = \frac{1}{(100000 \times 2^4)} = \frac{1}{(100000)} \times \frac{1}{(2^4)} = 10^{-5} \times \frac{1}{(2^4)}\)

For Quantity B:

Doing the same for QB:
\(\frac{1}{(5^6 \times 2^{10})} = 10^{-6}\times \frac{1}{(2^{4})}\)


Due to the fact that it is the same fraction in both quantities (an additional zero does not make a difference), the sum of their digits should be the same. Therefore, option C.
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Re: The sum of all the digits of 1/(5^5 * 2^9) when it is written in [#permalink]
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