noTh1ng
Can anyone else give it a try? To be honest I still don't really understand it, even with the already posted solutions...
It took me long to solve but this is how I eventually got to the right answer:
Range = Greatest less the smallest (number in the sequence)
Even before I look at the statements, I can see that I have an EVEN exponent a^2 and an ODD one a^5 . . . I already know they need to tell me whether a is negative or positive. (Requirement 1)
And then, I can also see that I have fractions in the sequence a/2 and a/5 . . . I already know they need to tell me whether a is FRACTION or an INTEGER (Requirement 2)
By "pushing the question" as Chris advised, I know that the statement/s are only sufficient if they give me both of my requirements
Now looking at the statements:
S1: only tells me a is NEGATIVE, only meets one of my requirements. Therefore I/S (insufficient)
S2: only tells me a^5 is less than a. The rules tell me that this can be the case if a is NEGATIVE or if a is a FRACTION. Again, doesn't completely meet my requirements. Therefore I/S
Together: I know a is NEGATIVE. This means that a^5 will ALWAYS be the smallest number in the sequence. And since all the other numbers in the sequence will be negative, a^2 will always be the only POSITIVE one and therefore the LARGEST. With this information I can find the range.
Hope that helps.