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a-(1/b)=/0
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Updated on: 22 Jan 2021, 13:41
Updated on: 22 Jan 2021, 13:41
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Question Stats:
100% (00:27) correct
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Quantity A |
Quantity B |
The reciprocal of \(a-(\frac{1}{b})\) |
\(\frac{b}{(ab-1)}\) |
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.
Why is the answer C?
Any two numbers whose product equal positive 1 are reciprocals. The reciprocal of a fraction is not just the "flip" of the fraction.
E.g. The reciprocal of √3 can be (√3)/3
Therefore, the reciprocal of a-(1/b) might not just be b/(ab-1)? So the answer should be D?
a-(1/b)=/0
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22 Jan 2021, 13:42
22 Jan 2021, 13:42
Expert Reply
Please Sir format the QCQ questions like you see now.
Follow the instructions in one easy step
https://gre.myprepclub.com/forum/how-to-po ... 12752.html
\(\frac{a-1}{b}\)
\(\frac{ab-1}{b}\)
The reciprocal
\(\frac{b}{ab-1}\)
The two quantities are equal
reciprocal_fraction_example.jpg [ 12.5 KiB | Viewed 1506 times ]
For better understanding see our Quant book https://gre.myprepclub.com/forum/gre-math- ... -2609.html
Regards
Follow the instructions in one easy step
https://gre.myprepclub.com/forum/how-to-po ... 12752.html
\(\frac{a-1}{b}\)
\(\frac{ab-1}{b}\)
The reciprocal
\(\frac{b}{ab-1}\)
The two quantities are equal
Quote:
The reciprocal of a fraction is just switching the numerator (top number) and the denominator (bottom number).
Attachment:
reciprocal_fraction_example.jpg [ 12.5 KiB | Viewed 1506 times ]
For better understanding see our Quant book https://gre.myprepclub.com/forum/gre-math- ... -2609.html
Regards
Re: a-(1/b)=/0
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23 Jan 2021, 15:42
23 Jan 2021, 15:42
I solved this problem using the matching operations method. Quantity A can be written as 1/(a-(1/b)). Multiply both sides by a-(1/b) and ab-1 and you are left with ab-1 on both sides of the equation. Thus C is the correct answer. Alternatively, you could solve using test values. For instance, if a=2 and b=2, both quantities will equal 2/3.
