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Pls help me understand the flaw with the second stmnt

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Pls help me understand the flaw with the second stmnt

by [email protected] » Sat Dec 21, 2013 9:45 pm
In this question why is the second stmnt not sufficient in itself?

Please correct me- the second stmnt says the sum of negative numbers is 10.6 less than the sum of positive numbers which means:

The sum of negative numbers will always be negative right? for example -2+(-3)+(-6)=-11 so wudnt it imply the x-(-y)=x+y (wherein x is the sum of positive numbers and y is the sum of negative numbers. And the second statement gives us the difference between the sums of negative and positive numbers thereby we get the equation= x-(-y)=10.86
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by Patrick_GMATFix » Sat Dec 21, 2013 10:25 pm
What is the sum of all 50 numbers in a list?

1) The sum of the positive numbers in the list is 7.3

2) The sum of the negative numbers in the list is 10.6 less than the sum of the positive numbers
In your logic you said that y was the sum of negatives. In that case, the difference between the sum of positives and the sum of negatives should be expressed as the difference between x and y --> x-y. x-(-y) = x+y is really the sum of the sums, not the difference between the sums.

Suppose for instance that the numbers were {-2, -1, 1, 2}. The sum of negatives is -3, so y=-3. The sum of positives is 3. The difference between the sums is (x)-(y) = (3)-(-3) = 6. What you suggested, x-(-y) is really 3-(3)=0 (since y=-3, -y=3).

I discuss this question in full (along with all OG questions since the OG 10) in the GMATFix App. The solution below was taken from the App.

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