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Sonia0106
Statement 1: The average of List B is 5/2.
We are already given that List B records number of defective units in each box (including the boxes that have no defects) but we are concerned about the mode of the List B and hence what is the mode of # of defective units.

In statement 1, we are given the average but we don't know how many numbers are there in the set and how well they are spaced, it is difficult to comment on the mode.
So insufficient.

Statement 2: The sum of List A is 2x/3
Since list A will contain either 1 or 0, we can infer that 2x/3 will be an integer and hence x is a multiple of 3 (3k,6k etc).
So if # of terms are 3, the sum is 2 and thus 1 defective box (and not unit) with a value 0.
if # of terms are 6, the sum is 4 and thus 2 defective boxes (and not units)

But what we can infer from here is that the number of defective boxes are half of non-defective boxes. Therefore, the mode will always be ZERO.

Hence sufficient.

chetan2u - Is the reasoning correct?

Yes, you are absolutely correct.
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As per this line "She also records in List B the number of defective units in each box" and as we know from statement 2 that 2/3rd of the boxes is not defective hence List B would contain 2x/3 Zeroes making it the Mode.

Option B
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sanjitscorps18
As per this line "She also records in List B the number of defective units in each box" and as we know from statement 2 that 2/3rd of the boxes is not defective hence List B would contain 2x/3 Zeroes making it the Mode.

Option B

sanjitscorps18

Can you please explain how are you directly inferring 2/3 of the boxes are not not defective? I did the whole calc to understand.
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sanjitscorps18
As per this line "She also records in List B the number of defective units in each box" and as we know from statement 2 that 2/3rd of the boxes is not defective hence List B would contain 2x/3 Zeroes making it the Mode.

Option B

sanjitscorps18

Can you please explain how are you directly inferring 2/3 of the boxes are not not defective? I did the whole calc to understand.

If you closely inspect statement 2, it says that the sum if 2x/3. As per the question stem, it is written that List A only comprises of 1 for a non-defective box and 0 for a defective box.
As per statement 2, if total boxes are 'x' and after adding values in List 1, I get 2x/3 as the sum then I can safely conclude that 1 * 2x/3 is the sum of the non-defective boxes.

For e.g., if there are 6 total boxes, then as per statement 2, adding numbers in List A, I would get 2 x 6/3 = 4, because I noted 4 x Ones (non-defective boxes) and Two zeroes (defective boxes). Hope this clarifies.
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