If the average of four numbers is 35, how many of the number

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by Brent@GMATPrepNow » Sun Aug 25, 2019 3:57 pm

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BTGmoderatorDC wrote:If the average of four numbers is 35, how many of the numbers are less than 35?

(1) None of the numbers are exactly 35

(2) Two of the numbers are exactly 33

OA E

Source: Veritas Prep
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Given: The average of four numbers is 35

Target question: How many of the numbers are less than 35?
If we're able to see that the statements FEEL insufficient, and we're able to come up with some counter-examples in our head, then we can head straight to...
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Statements 1 and 2 combined
There are several sets of 4 values that satisfy BOTH statements. Here are two:
Case a: The numbers are {33, 33, 37, 37}. In this case, the answer to the target question is there are TWO numbers less than 35
Case b: The numbers are {33, 33, 34, 40}. In this case, the answer to the target question is there are THREE numbers less than 35
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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