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OG 13 DS Q46

by travelteer » Sun Jun 15, 2014 8:07 am
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 correct answer seems to be E.

Now I am not even sure how statement 1 yields tenths digits: 0,1,2,3 OR
statement 2 yields tenths digits: 2,3,4,...,9
Let alone the combined result from the two statements as 2 or 3.

Can someone please explain this to me? Thanks so much. I have looked through the OG13 as well as the MGMAT explanations and I couldn't quite make sense.
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Source: — Data Sufficiency |

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by Brent@GMATPrepNow » Sun Jun 15, 2014 8:20 am
travelteer 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
Target question: What is the tenths digit in the decimal representation of a certain number?

Statement 1: The number is less than 1/3
In other words, the number is less than 0.3333...
There are several values that satisfy this condition. Here are two:
Case a: the number is 0.31, in which case the tenths digit is 3
Case b: the number is 0.29, in which case the tenths digit is 2
Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT

Statement 2: The number is greater than 1/4
In other words, the number is greater than 0.25
There are several values that satisfy this condition. Here are two:
Case a: the number is 0.31, in which case the tenths digit is 3
Case b: the number is 0.29, in which case the tenths digit is 2
Since we cannot answer the target question with certainty, statement 2 is NOT SUFFICIENT

Statements 1 and 2 combined
So, we now now that the number is greater than 0.25 and less than 0.3333..
There are still several values that satisfy this condition. Here are two:
Case a: the number is 0.31, in which case the tenths digit is 3
Case b: the number is 0.29, in which case the tenths digit is 2
Since we cannot answer the target question with certainty, the combined statements are NOT SUFFICIENT

Answer = E

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
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by Brent@GMATPrepNow » Sun Jun 15, 2014 8:26 am
travelteer wrote: Now I am not even sure how statement 1 yields tenths digits: 0,1,2,3
If the number is less than 0.3333..., then some possible values of the number are: 0.01, 0.12, 0.26, and 0.31
As you can see, the tenths digit can be 0, 1, 2 or 3
travelteer wrote: ...OR
statement 2 yields tenths digits: 2,3,4,...,9
If the number is greater than 0.25, then some possible values of the number are: 0.29, 0.32, 0.46, 0.51, 0.64, etc
As you can see, the tenths digit can be 2, 3, 4, 5,... 9

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
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