DS: If x>0.09/k, is x>0.05?

[cesar.rodriguez.blanco]

I do not know how to deal woth this DS!!
Source:beatthegmat

If x>0.09/k, is x>0.05?
a) k>0.001
b) k<0.01

[Ben Ku]

Let's first look at a simpler problem. If a > b, is a > 5?

Here, we can see two possibilities:
If b <= 5, then the answer is YES, the statement is sufficient.
If b > 5, then the answer is MAYBE, the statement is insufficient.

In the given question, we can use the same analogy:
If 0.09/k <= 0.05, then the statement is sufficient.
If 0.09/k > 0.05, then the statement is insufficient.

For statement (1), we can rewrite k as GT 0.001 (GT means greater than).
so 0.09/k = 0.09/GT 0.001 = LT90.
Because 0.09/k < 90, it's insufficient.

For statement (2), we can rewrite k as LT 0.01 (LT means less than).
so 0.09/k = 0.09/LT0.01 = GT 9
Because 0.09/k > 9, it's insufficient. [editor: see revised analysis below]

From statements (1) and (2) together,
9 < 0.09/k < 90, we know 0.09/k > 0.05. Together the statements are sufficient.

Based on this question, I would say the answer is (C). However, the numbers aren't really close, so either the question is written poorly, or it was copied incorrectly. Let me know if that helps.

[RonPurewal]

Let's first look at a simpler problem. If a > b, is a > 5?

Here, we can see two possibilities:
If b <= 5, then the answer is YES, the statement is sufficient.
If b > 5, then the answer is MAYBE, the statement is insufficient.

In the given question, we can use the same analogy:
If 0.09/k <= 0.05, then the statement is sufficient.
If 0.09/k > 0.05, then the statement is insufficient.

For statement (1), we can rewrite k as GT 0.001 (GT means greater than).
so 0.09/k = 0.09/GT 0.001 = LT90.
Because 0.09/k < 90, it's insufficient.

For statement (2), we can rewrite k as LT 0.01 (LT means less than).
so 0.09/k = 0.09/LT0.01 = GT 9
Because 0.09/k > 9, it's insufficient. [editor: see revised analysis below]

From statements (1) and (2) together,
9 < 0.09/k < 90, we know 0.09/k > 0.05. Together the statements are sufficient.

Based on this question, I would say the answer is (C). However, the numbers aren't really close, so either the question is written poorly, or it was copied incorrectly. Let me know if that helps.

this analysis is correct, except for the analysis of statement 2.
if x is greater than 0.09/k, which in turn is greater than 9, then x itself is greater than 9. that would be sufficient to determine that x is greater than the much smaller figure of 0.05.
HOWEVER,
statement (2) is still insufficient because of the possibility of negative values for k. i.e., nothing is stopping k from being, say, k = -1. in that case, we'd have x > -0.09, so that would genuinely be insufficient.

together: in this case, we have 0.001 < k < 0.01, so that 0.09/0.001 > 0.09/k > 0.09/0.01, which simplifies to 90 > k > 9. so this is sufficient.

answer should be (c)

[vijaykumar.kondepudi]

Let's first look at a simpler problem. If a > b, is a > 5?

Here, we can see two possibilities:
If b <= 5, then the answer is YES, the statement is sufficient.
If b > 5, then the answer is MAYBE, the statement is insufficient.

In the given question, we can use the same analogy:
If 0.09/k <= 0.05, then the statement is sufficient.
If 0.09/k > 0.05, then the statement is insufficient.

For statement (1), we can rewrite k as GT 0.001 (GT means greater than).
so 0.09/k = 0.09/GT 0.001 = LT90.
Because 0.09/k < 90, it's insufficient.

For statement (2), we can rewrite k as LT 0.01 (LT means less than).
so 0.09/k = 0.09/LT0.01 = GT 9
Because 0.09/k > 9, it's insufficient. [editor: see revised analysis below]

From statements (1) and (2) together,
9 < 0.09/k < 90, we know 0.09/k > 0.05. Together the statements are sufficient.

Based on this question, I would say the answer is (C). However, the numbers aren't really close, so either the question is written poorly, or it was copied incorrectly. Let me know if that helps.

Hi,
I am not sure if I understood ur simpler problem logic :

If a > b, is a > 5?

Here, we can see two possibilities:
If b <= 5, then the answer is YES, the statement is sufficient.
If b > 5, then the answer is MAYBE, the statement is insufficient.

I think these cases need to be reversed.
Lets assume the following values : a=20, b=10
If b > = 5; It obviously means that a (a > b from question) is GT 5.
But, if b < 5; we are not sure if a> 5, even if a > b.

Please clarify.

Thanks

[Ben Ku]

If a > b, is a > 5?

Here, we can see two possibilities:
If b <= 5, then the answer is YES, the statement is sufficient.
If b > 5, then the answer is MAYBE, the statement is insufficient.

You are correct. The two possibilities should be:
If b >= 5, then the answer is YES, the statement is sufficient.
If b < 5, then the answer is MAYBE, the statement is insufficient.

Sorry for the confusion.