# Apr 25 SAT Question of the Day & ACT QotD

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. If you are seeing this in my blog, do the SAT Question of the Day by clicking on this link:

http://sat.collegeboard.org/practice/sat-question-of-the-day?src=R&questionId=20130425 (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 E.  OMG!  Yes, you could have done this the SAT staff’s way but why would you?  Look at their calculations and you see that it would be Sunday afternoon when you finished changing all the fractions to a common denominator and then  putting all that stuff into your calculator!

You can do this question in your head if you don’t get intimidated (Pillar VI).  First, the 1’s in each equation cancel; so, don’t worry about them.  Second, each fraction in s gets you 1/2 of the way to a whole from where you were when you added it.  Here’s what I mean: 1/2 gets you half way from 0 to 1; then 1/4 gets you half way from 1/2 to 1 which is 3/4 (leaving you 1/4 away from 1).  Then 1/8 splits the remaining 1/4 in half; you are 1/8 of the way from 1.  Then the 1/16 splits that remaining 1/8 in half.  Do you see the pattern?  (Wizard is always saying, “The world of math is a world of patterns!) Each fraction tells you how close you are to 1: 1/2 way, 1/4 way, 1/8, etc.  That means that the 1/32 means you are within 1/32 of getting to 1 or s=1-31/32!  Since t=1/2(s), the answer is 1/64.

What do I want you to learn from this question?  There are two things.  First, if you find yourself doing a lot of math calculations, you are doing way too much work.  I don’t care what the SAT (or ACT) staff puts in their explanations; often it is a waste of time.  Practicing is going to help you see the shortcut ways to the answer.  Keep reading my blog.  Second, “The world of math is a world of patterns.”  While practicing, watch for patterns.  You will find them on both the SAT and ACT math tests.

Let’s move on to see what the ACT folks have for us today.

http://www.act.org/qotd/ (The ACT staff does not put a date on their questions so if you click on an archived blog, you’ll get today’s question and the old explanation. Sorry. The SAT staff has dated their questions; so, the archive is helpful. The ACT folks simply don’t do that.)