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Re: 98^7 [#permalink]
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pranab01 wrote:
IlCreatore wrote:
Column A can be rewritten as \(\frac{7^{14}2^7}{2^{63}}=\frac{2^7}{7^{49}}\). Thus, column A and B are equal and answer is C!



The ans should be -

Column A & Column B is

\(\frac{{7^{14}2^7}}{{7^{63}}}=\frac{{2^7}}{{7^{49}}}\)

which comes to option C


You are right, I made a typo!
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Re: 98^7 [#permalink]
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Carcass wrote:

This question is part of GREPrepClub - The Questions Vault Project




Quantity A
Quantity B
\(\frac{98^7}{7^{63}}\)
\(\frac{2^7}{7^{49}}\)




We can solve this question using matching operations

Given:
Quantity A: (98^7)/(7^63)
Quantity B: (2^7)/(7^49)

Multiply both quantities by 7^63 to get:
Quantity A: 98^7
Quantity B: (2^7)(7^14)

Rewrite 7^14 as (7^7)(7^7) to get:
Quantity A: 98^7
Quantity B: (2^7)(7^7)(7^7)

A nice rule says (a^k)(b^k) = (ab)^k

Apply this rule to quantity B to get:
Quantity A: 98^7
Quantity B: (2 x 7 x 7)^7

Simplify to get:
Quantity A: 98^7
Quantity B: 98^7

Answer: C

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Re: 98^7 [#permalink]
IlCreatore wrote:
Column A can be rewritten as \(\frac{7^{14}2^7}{7^{63}}=\frac{2^7}{7^{49}}\). Thus, column A and B are equal and answer is C!



Nice .. it was hard to imagine that.. great :)
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Re: Which is greater 98^7/7^{63} or 2^7/7^{49} [#permalink]
How do you go from 98^7 to 7^14*2^7?
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Re: Which is greater 98^7/7^{63} or 2^7/7^{49} [#permalink]
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giancarlojr wrote:
How do you go from 98^7 to 7^14*2^7?


We use the rule that says \((abc)^n = a^nb^nc^n\)

\(98 = (7)(7)(2)\)

So, \(98^7 = [(7)(7)(2)]^7\)

So, according to the above rule, we can write: \(98^7 = (7^7)(7^7)(2^7)\)

Since \((7^7)(7^7) = 7^{14}\), we can write: \(98^7 = (7^{14})(2^7)\)

Does that help?
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Re: Which is greater 98^7/7^{63} or 2^7/7^{49} [#permalink]
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that's perfect thanks!
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Re: Which is greater 98^7/7^{63} or 2^7/7^{49} [#permalink]
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Thank you greenlight test prep. best explanation!
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Re: Which is greater 98^7/7^{63} or 2^7/7^{49} [#permalink]
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