What is the tenths digit in the decimal representation of a

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What is the tenths digit in the decimal representation of a [#permalink]

24 Sep 2012, 05:12

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The Official Guide for GMAT® Review, 13th Edition - Quantitative Questions Project

What is the tenths digit in the decimal representation of a certain number?

(1) The number is less than 1/3
(2) The number is greater than 1/4

Practice Questions
Question: 46
Page: 279
Difficulty: 600

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Re: What is the tenths digit in the decimal representation of a [#permalink]

24 Sep 2012, 05:12

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SOLUTION

What is the tenths digit in the decimal representation of a certain number?

(1) The number is less than 1/3.

(2) The number is greater than 1/4.

Each statement alone is clearly insufficient. When taken together we have 0.25<x<0.333.... Hence the tenths digit can be 2 (for example if x= 0.251) or 3 (for example if x=0.3). Not sufficient.

Answer: E.
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Re: What is the tenths digit in the decimal representation of a [#permalink]

24 Sep 2012, 05:28

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The number is less than 1/3
(2) The number is greater than 1/4
1) Tenth digit can be 0,1,2,3 - Insufficient
2) Tenth digit can be 2,3,4,5..-Insufficient
1+2) .25<x<.333 - x can be 2,3-Insufficient
Answer E
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Re: What is the tenths digit in the decimal representation of a [#permalink]

24 Sep 2012, 09:28

Bunuel wrote:

What is the tenths digit in the decimal representation of a certain number?

(1) The number is less than 1/3
(2) The number is greater than 1/4

lets assume N = 0.xyz...

(1)
N < 1/3
N < 0.333333

Now, N can be 0.234 or 0.3111 or 0.121212
Basically, tenths digit can be 0 or 1 or 2 or 3
So, we cant say what would be the tenths digit
hence not sufficient.

(2)
N > 1/4
N > 0.25
Now, here digit can be 2,3,4,5,6,7,8,9
Hence this is also not sufficient

combining (1) and (2), the tenths digit can be either 2 or 3.
So, we can't answer the exact digit.

Hence E
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Re: What is the tenths digit in the decimal representation of a [#permalink]

28 Sep 2012, 05:06

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Re: What is the tenths digit in the decimal representation of a [#permalink]

28 Sep 2012, 07:13

Quote:

What is the tenths digit in the decimal representation of a certain number?

(1) The number is less than 1/3
(2) The number is greater than 1/4

1) 1/3 is 0.33 (periodic) but could be also 1/4 = 0.25 so we have a 3 and a 2 . insuff

2) the same: the number could be 1/4 or 1/5 or 1/10 . insuff

1) + 2) x is between 1/3 and 1/4 but a lot of infinite value we could find

E is the answer
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When to actually consider a negitive (or unspecified bounds) [#permalink]

21 Mar 2013, 22:32

As I am going through the OG12 and other sources, I notice the use of when to consider a negitive (or similar) inconsistent during answer explainations from the question makers.

For example, today I came across this DS question:

OG12 question 43 page 276
What is the tenths digit in the decimal representation of a certain number?

1) the number is less than 1/3
2) the number is greater than 1/4

The OA states:

1) Since the number is less than 1/3, the tenths digit can be 0,1,2, or 3; NOT sufficient
2) Since the numebr is greater than 1/4, the tenths digit can be 2,3,4, ..., 9; NOT sufficient

My contention is that the OA doesn't take into consideration negitive numbers for S1, nor numbers greater than 1 for S2. Because of this, the tens digit could be any number 0-9 for either S1 or S2. Of course, in this question it doesn't affect the outcome of the correct answer being E; but I have seen questions inconsistently consider negitives or not

Any insight as to when to ignore negitives (or other bounds like non-integer/fractions) despite the question not stating it in any manner?

Thanks

When to actually consider a negitive (or unspecified bounds) [#permalink] 21 Mar 2013, 22:32

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What is the tenths digit in the decimal representation of a

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What is the tenths digit in the decimal representation of a

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