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Select 5 numbers from the nine numbers, namely 1~9
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31 Jul 2020, 21:26
31 Jul 2020, 21:26
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Question Stats:
23% (01:32) correct
76% (02:02) wrong based on 42 sessions
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Select 5 numbers from the nine numbers, namely 1~9 (inclusive), to sum up
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.
Quantity A |
Quantity B |
The number of possible ways that the sum of these five numbers is 22 |
The number of possible ways that the sum of these five numbers is 28 |
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.
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Re: Select 5 numbers from the nine numbers, namely 1~9
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05 Aug 2020, 05:34
05 Aug 2020, 05:34
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lazyashell wrote:
Select 5 numbers from the nine numbers, namely 1~9 (inclusive), to sum up
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.
Quantity A |
Quantity B |
The number of possible ways that the sum of these five numbers is 22 |
The number of possible ways that the sum of these five numbers is 28 |
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.
In my opinion, this question is beyond the scope of the GRE.
Unless I'm missing an alternative solution, this question requires us to know something about "expected values," which is not tested on the GRE
It goes a little something like this:
The average value of 1,2,3,4,5,6,7,8 and 9 is 5.
So, if we select 5 of those numbers, the EXPECTED SUM = (5)(5) = 25
That is, the most likely SUM will be 25
Since 22 and 28 are equal distances from 25, the sums of 22 and 28 are equally likely
Answer: C
Cheers,
Brent
General Discussion
Re: Select 5 numbers from the nine numbers, namely 1~9
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04 Aug 2020, 18:46
04 Aug 2020, 18:46
Would love to see this done algebraically instead of just thinking through the possible combos!
