Explanation
We don't know whether
u and v are integers, so they may
or may not be, but they are positive. That means that
will be less
than 1 if and only if u is less than v. If, on the other hand, v is greater than u, then
will be
greater than 1. For example,
and
are both less
than 1, but
and
are both
greater than 1. We can keep this in mind when evaluating
the statements, which we can do separately first.
Statement (1): we already knew that
was positive.
The fact that it's greater than one when squared means it was already greater
than one. That subject is covered in the math review of this course and also in the official testmaker's
rubric, and you can see it by playing with numbers. So, we can conclude that
. Is that enough to know which is greater? Nope. We
can see by cases: u could be a
billion and v could be 1, or vice
versa. So we don't have sufficient information to identify which is great.
Statement (1) is insufficient.
Statement (2), after the first statement, is like a gift.
If we had noticed it initially, we might have evaluated it before Statement
(1); that's no crime as long as we evaluate each of them separately before even
daring to contemplate whether we have to combine them. If we add v to both sides of this statement, we obtain
. So we have data that u is larger than v. That means that
will always
be greater than 1. We have information to answer the question in a manner
definitive for all cases, so Statement (2) is sufficient.
The correct answer is (B).
If you believe you have found an error in this question or explanation, please contact us and include the question title or URL in your message.