# ACT & SAT Question of the Day: Feb. 27, 2014

If you are reading this in an email you received from me, do not click the link to sat.collegeboard.org below. Use the link to my website that is farther down on the email.

http://sat.collegeboard.org/practice/sat-question-of-the-day?questionId=20140227&oq=1 (This link takes you to today’s question. If you use my archive, you will see the question related to my SAT explanation for that date.)

The answer is B.  If you know what “defined” or “not defined” means, this question is a snap.  You cannot divide by 0 so “not defined” simply means anytime there is a 0 in the denominator you have an “undefined” value.

How could you get a 0 in the denominator?  If x is -3, (x +3) would be 0.  If x is 4, (x – 4) would be zero.  Therefore, either value for x makes the denominator 0 because when you multiply the binomials in the denominator 0 times either one give you 0.  Look!  Answer B is -3.

What does this question remind us to do before the test?  You need to review your math vocabulary.  What’s the best way to do that?  Do a boat load of practice questions.  Keep up with the QotD and use the Official SAT Study Guide as well as the Real ACT Prep Guide.  That will do it.

I wonder what the ACT folks have up their sleeves this morning!

The answer is G.  This question helps make the point I was making above.  Math vocabulary is important.  Questions like this one get to be tricky if you aren’t being very careful.  What makes this question tricky is that they show a fraction, , and a ratio, , that look exactly alike.  That is almost not fair!  How do you tell them apart?  Vocabulary.  The  is followed by the word “of” which means it is a fraction.  But you know the answer must be a “ratio” because they tell you that in the question.

Because one out of 40 bulbs is bad, then 39 out of 40 are good making the ratio 1 bad bulb to 39 good bulbs or 1:39.  Expressing the ratio the other way is .  It looks like a fraction but it isn’t.  Generally, fractions are shown with a / rather than a flat -.  I guess the ACT folks had a bad weekend and wanted to take it out on us.  I don’t remember a time on the SAT or ACT when they did this tricky notation on another question.  But it tells us how important it is to remember our math vocabulary.  Doing so today helped us out trick the trickster!

Our summer trip is coming together.  We will be in Tallahassee on June 4 and Pensacola on the 5th.  We are trying to set up meetings in Memphis and Northwest Arkansas the following week.  After stopping in Denver (exact date and location undetermined), on June 23 or 24 we will be in Summit County, CO.  From there we head to Washington via Salt Lake City.  Eventually we will be in Alaska.  Coming back, we have stops in Billings, MT, Sioux Falls, SD, South Bend, IN, and perhaps to Cleveland and then Charlotte.  Do you live along our 4-month route?  If so, let us know and we’ll try to fit you in.

We will be posting our summer itinerary soon.  Keep an eye on it.  You never know where we may show up.  There will be some open dates and maybe you can help fill them in.

Bob Alexander, the “SAT and ACT Wizard”