billyr wrote:Why statement 1 alone suff?
i thought statement 1 is insuff since the symbol can be addition or multiplication?
Thanks
The good news is that you're right. The bad news is that you're also wrong!
You're 100% correct that, based on statement (1), we can't determine if the operation is addition or multiplication.
However, you're not answering the correct question. In Data Sufficiency, we have to make sure our focus is in the right place.
The question is NOT: "which of the 4 operations does the triangle represent?" The question is: "is the equation listed true?"
Since that equation holds true for BOTH addition and multiplication, statement (1) gives us a definite "YES" answer to the question: sufficient.
Statement (2), on the other hand, holds true for addition and subtraction. The original equation holds true for addition, but NOT for subtraction, so (2) can give us both a "YES" and a "NO" answer: insufficient.
(1) is sufficient alone, (2) isn't: choose (A).
