Today’s SAT question of the day is an easy algebra question and a great chance to review our algebra basics.

#1 rule of algebra on the SAT: answer the right question. Don’t answer a question that isn’t being asked!

So, they want to know what x – y = when (x/y) = 3 and x =12.

Let’s start by substituting 12 for x, since we are told that x = 12.

(12/y) = 3

12 = 3y

(12/3) = y

4 = y

But 4 is not an answer choice!  That’s because we need to find x – y, not y itself.

12 – 4 = 8, or choice D

We got lucky this time by not having 4 as an answer choice, but typically it would be among the wrong answers as a trap. Don’t fall for it!