If r ≠ 1 and if sr/(s - r) = 1, what is the value of s in terms of r? Choose the correct choice from the following choices:	A) (r+1)/r	B) (r - 1)/r	C) r/(r + 1)	D) r/(1-r)	E) (1 - r)/r
This question comes with a particular 'quirk' (one that you probably won't see on Test Day). The GMAT won't test you on the concept of undefined numbers (re: numbers divided by 0), so any time that this concept is a possibility, the question writers have to add a restriction that removes the option that a 0 could occur in the denominator.   Here, we're told that B CANNOT = 1, which is a bit strange because that restriction doesn't seem to impact the original equation much. In fact, it impacts JUST ONE of the answer choices - so you have to ask WHY that restriction is even there. It's actually because that one answer is the correct one.   Final Answer:   r/(1-r)
<result>D</result>
If r ≠ 1 and if sr/(s - r) = 1, what is the value of s in terms of r?