d = 0.7abc
In the decimal representation of d above, is a + b + c > 15?
(1) When d is rounded to the nearest thousandth, the result would be 0.765
(2) When d is rounded to the nearest hundredth, the result would be 0.77
d = 0.7abc In the decimal representation of d above, is a +
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Hi Mechmeera,
This DS question is based on rounding "rules"; you can TEST VALUES to prove the correct answer (although you have to be thorough).
We're given that D = 0.7ABC (where A, B and C represent digits). We're asked if A+B+C > 15. This is a YES/NO question.
Fact 1: When D is rounded to the nearest thousandth, the result would be 0.765
This means that D could be 'rounded up' or 'rounded down'
IF....
D = .7649
Then 6+4+9 = 19 and the answer to the question is YES
IF....
D = .7651
Then 6+5+1 = 12 and the answer to the question is NO
Fact 1 is INSUFFICIENT
Fact 2: When d is rounded to the nearest hundredth, the result would be 0.77
This too can be the result of 'rounding up' or 'rounding down'
IF...
D = .7650
6+5+0 = 11 and the answer to the question is NO
IF...
D = .7749
7+4+9 = 20 and the answer to the question is YES
Fact 2 is INSUFFICIENT
Combined, we know...
When D is rounded to the nearest thousandth, the result would be 0.765
When D is rounded to the nearest hundredth, the result would be 0.77
This limits down the possibilities. D must begin with .765 (so that when D is 'rounded up' it becomes .77). It's the missing "C" digit that impacts the question here. Note, that .765 has to be the result from rounding to the nearest thousandth, so "C" MUST be one of the digits from 0-4, inclusive (if it was 5-9, then D would = .766).
IF....
D = .7650
6+5+0 = 11 and the answer to the question is NO
IF....
D = .7654
6+5+4 = 15 and the answer to the question is NO
The other 3 possibilities would fall 'in between' these two TESTS and would also give us NO answers.
Combined, SUFFICIENT
Final Answer: C
GMAT assassins aren't born, they're made,
Rich
This DS question is based on rounding "rules"; you can TEST VALUES to prove the correct answer (although you have to be thorough).
We're given that D = 0.7ABC (where A, B and C represent digits). We're asked if A+B+C > 15. This is a YES/NO question.
Fact 1: When D is rounded to the nearest thousandth, the result would be 0.765
This means that D could be 'rounded up' or 'rounded down'
IF....
D = .7649
Then 6+4+9 = 19 and the answer to the question is YES
IF....
D = .7651
Then 6+5+1 = 12 and the answer to the question is NO
Fact 1 is INSUFFICIENT
Fact 2: When d is rounded to the nearest hundredth, the result would be 0.77
This too can be the result of 'rounding up' or 'rounding down'
IF...
D = .7650
6+5+0 = 11 and the answer to the question is NO
IF...
D = .7749
7+4+9 = 20 and the answer to the question is YES
Fact 2 is INSUFFICIENT
Combined, we know...
When D is rounded to the nearest thousandth, the result would be 0.765
When D is rounded to the nearest hundredth, the result would be 0.77
This limits down the possibilities. D must begin with .765 (so that when D is 'rounded up' it becomes .77). It's the missing "C" digit that impacts the question here. Note, that .765 has to be the result from rounding to the nearest thousandth, so "C" MUST be one of the digits from 0-4, inclusive (if it was 5-9, then D would = .766).
IF....
D = .7650
6+5+0 = 11 and the answer to the question is NO
IF....
D = .7654
6+5+4 = 15 and the answer to the question is NO
The other 3 possibilities would fall 'in between' these two TESTS and would also give us NO answers.
Combined, SUFFICIENT
Final Answer: C
GMAT assassins aren't born, they're made,
Rich
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[email protected] wrote:Hi Mechmeera,
This DS question is based on rounding "rules"; you can TEST VALUES to prove the correct answer (although you have to be thorough).
We're given that D = 0.7ABC (where A, B and C represent digits). We're asked if A+B+C > 15. This is a YES/NO question.
Fact 1: When D is rounded to the nearest thousandth, the result would be 0.765
This means that D could be 'rounded up' or 'rounded down'
IF....
D = .7649
Then 6+4+9 = 19 and the answer to the question is YES
IF....
D = .7651
Then 6+5+1 = 12 and the answer to the question is NO
Fact 1 is INSUFFICIENT
Fact 2: When d is rounded to the nearest hundredth, the result would be 0.77
This too can be the result of 'rounding up' or 'rounding down'
IF...
D = .7650
6+5+0 = 11 and the answer to the question is NO
IF...
D = .7749
7+4+9 = 20 and the answer to the question is YES
Fact 2 is INSUFFICIENT
Combined, we know...
When D is rounded to the nearest thousandth, the result would be 0.765
When D is rounded to the nearest hundredth, the result would be 0.77
This limits down the possibilities. D must begin with .765 (so that when D is 'rounded up' it becomes .77). It's the missing "C" digit that impacts the question here. Note, that .765 has to be the result from rounding to the nearest thousandth, so "C" MUST be one of the digits from 0-4, inclusive (if it was 5-9, then D would = .766).
IF....
D = .7650
6+5+0 = 11 and the answer to the question is NO
IF....
D = .7654
6+5+4 = 15 and the answer to the question is NO
The other 3 possibilities would fall 'in between' these two TESTS and would also give us NO answers.
Combined, SUFFICIENT
Final Answer: C
GMAT assassins aren't born, they're made,
Rich
since it said in Fact 1: When D is rounded to the nearest thousandth, the result would be 0.765.
it is not compulsory that b=5 c=0-4
we can also consider b=4 and c=5-9 in this case sum will be more than 15.
then how can we conclude c.
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Give Rich's explanation another read. He considers D = .7649 when evaluating statement 1 alone. When testing the statements together, we have to incorporate the information from statement 2, "when d is rounded to the nearest hundredth, the result would be 0.77." Consequently, we can no longer consider .7649, because this value, rounded to the nearest hundredth, would be .76. This would violate statement 2.since it said in Fact 1: When D is rounded to the nearest thousandth, the result would be 0.765.
it is not compulsory that b=5 c=0-4
we can also consider b=4 and c=5-9 in this case sum will be more than 15.
then how can we conclude c.
- conquistador
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Thanks DavidDavidG@VeritasPrep wrote:Give Rich's explanation another read. He considers D = .7649 when evaluating statement 1 alone. When testing the statements together, we have to incorporate the information from statement 2, "when d is rounded to the nearest hundredth, the result would be 0.77." Consequently, we can no longer consider .7649, because this value, rounded to the nearest hundredth, would be .76. This would violate statement 2.since it said in Fact 1: When D is rounded to the nearest thousandth, the result would be 0.765.
it is not compulsory that b=5 c=0-4
we can also consider b=4 and c=5-9 in this case sum will be more than 15.
then how can we conclude c.
I just missed this point.
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Statement 1: When d is rounded to the nearest thousandth, the result would be 0.765.Mechmeera wrote:d = 0.7abc
In the decimal representation of d above, is a + b + c > 15?
(1) When d is rounded to the nearest thousandth, the result would be 0.765
(2) When d is rounded to the nearest hundredth, the result would be 0.77
Here, the range for d is as follows:
0.7645 ≤ d < 0.7655.
If d = 0.7645, then a+b+c = 15.
If d = 0.7646, then a+b+c > 15.
INSUFFICIENT.
Statement 2: When d is rounded to the nearest hundredth, the result would be 0.77.
Here, the range for d is as follows:
0.765 ≤ d < 0.775.
If d = 0.7650, then a+b+c < 15.
If d = 0.7659, then a+b+c > 15.
INSUFFICIENT.
Statements combined:
Statement 1: 0.7645 ≤ d < 0.7655.
Statement 2: 0.765 ≤ d < 0.775.
OVERLAP between the two ranges:
0.765 ≤ d < 0.7655.
Options for d:
0.7650, 0.7651, 0.7652, 0.7653, 0.7654.
In every case, a+b+c ≤ 15.
SUFFICIENT.
The correct answer is C.
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Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
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