ildude02 wrote:Ian Stewart wrote:robertpatrick wrote:I put choice B because I knew from the stem that 5^(x) < 1 already, there's no new information in number 1.
You don't know anything at all from the stem- it doesn't state any facts, just asks a question. I don't quite follow your logic, but it appears that you are assuming that the inequality in the stem is true. You cannot assume that- that's the question you need to answer.
But if the question(after reducing it) asks for if "5 ^ X < 1" and if the supporting statement says so, then why shouldn't we pick A as sufficient ? I'm confused, can you please explain what might be the reason we can't say that statement 1 is SUFFICIENT?
We CAN say that (1) is sufficient, that's why (b), which the OP chose, isn't the correct answer.
Robertpatrick started out great by simplifying the question, something that often makes life easier in DS. We can definitely reduce the question to:
is 5^x < 1?
However, Robertpatrick took that as information, rather than a question, and decided that (1) was insufficient because it just repeated what we already knew. Whenever a statement gives absolutely no new information (which is rare, but does happen sometimes on the GMAT), we immediately know that the statement is insufficient (and can also eliminate the "together" choice).
Here's an example:
If Bob drove from town A to town C at 20 mph, how long did the trip take?
(1) If Bob had driven at 10 miles per hour, it would have taken him twice as long.
Well, (1) might seem like useful information, but it's actually worthless, since it reduces to: "if you halve your speed, you double your time", which we can derive from the d=rt equation itself. If you faced this question on test day, you'd immediately elminiate (a), (c) and (d).