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Given that (3)^(a-b) = 1/81
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Updated on: 30 May 2018, 16:36
Updated on: 30 May 2018, 16:36
1
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Question Stats:
58% (00:50) correct
41% (00:27) wrong based on 34 sessions
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Given that \((3)^{(a-b)} = \frac{1}{81}\)
A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.
Please clear my doubt
there are 2 ways to see above problem
if we write (3)^(a-b) =3^a/3^b
then
3^a/3^b=1/81
a=0 and b=4
answer will be B
but similarly it can be seen as
(3)^(a-b) =3^(-4)
in this case a-b = -4
answer will be D
Quantity A |
Quantity B |
a |
b |
A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.
Please clear my doubt
there are 2 ways to see above problem
if we write (3)^(a-b) =3^a/3^b
then
3^a/3^b=1/81
a=0 and b=4
answer will be B
but similarly it can be seen as
(3)^(a-b) =3^(-4)
in this case a-b = -4
answer will be D
Originally posted by Sonalika42 on 30 Aug 2016, 02:50.
Last edited by Carcass on 30 May 2018, 16:36, edited 5 times in total.
Last edited by Carcass on 30 May 2018, 16:36, edited 5 times in total.
Added the OA
Re: Very confused
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30 Aug 2016, 03:21
30 Aug 2016, 03:21
2
@Sonalika,
in your 2nd case a-b=-4 => b= a+4
therefore b>a
I would have solved this way
\(3^{a-b}\)= \(\frac{1}{81}\)
=> \(\frac{1}{3^{b-a}}\) = \(\frac{1}{81}\)
therefore b>a
in your 2nd case a-b=-4 => b= a+4
therefore b>a
I would have solved this way
\(3^{a-b}\)= \(\frac{1}{81}\)
=> \(\frac{1}{3^{b-a}}\) = \(\frac{1}{81}\)
therefore b>a
Re: Very confused
[#permalink]
30 Aug 2016, 07:01
30 Aug 2016, 07:01
1
B clearly. Took A as -5 and B as -1 or take A as 1 and B as 5.
