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=20130506 (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. There’s nothing wrong with this sentence. That makes it “hard.” That is, lots of students miss it (56% as of right now) because they are expecting a mistake in the sentences and find one where one doesn’t exist. Remember that there will be a number of sentences that are perfectly fine; so, don’t make a mistake by finding a grammar error where one doesn’t exist.
What can be tricky is that you could rewrite this sentence by adding “that are” before “up to.” The sentence could read “…limestone layers that are up to 90 feet thick…” and it would be fine. You might think it sounds better and would want to change it in that way. However, there’s nothing wrong with the way it is and you don’t have to fix it even though you can edit it. That can make these sentences tricky. Be sure you are looking for absolute grammar and composition mistakes, not places you can rewrite sentences so they are more pleasing to you.
Let’s see what kind of trap the ACT folks have concocted 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.)
The answer is C. Some quick mental math eliminates three answers. 24 minutes is almost a half hour so doubling 4.8 leaves you with either 10 or 12 as answers. To do the exact math you have to convert 24 minutes to hours. There are 60 minutes per hour; so, 24/60 is 2/5 of an hour. Multiplying 4.8 times 5/2 gives you the right answer, 12.
Then there’s the “math teacher” way to do this question and the ACT staff provides you that explanation on the website. I’ll save myself a little typing and let you read about that way to do it.
What I’d like you to learn about the SAT and ACT from this question is that the test writers pick numbers that are easy to use. they didn’t pick 21 or 23 minutes; they picked 24. Why? That is because 24 minutes is 2/5 of an hour. Sometimes they pick 15 minutes or 20 minutes and those are 1/4 and 1/3 of an hour respectively. 6 minutes is 1/10 of an hour. 12 minutes is 1/5 of an hour. That means 24 is 2/5 because it is 2 times 12.
I used this insight into the test (they pick numbers “that work” or are easy to manipulate) to do this question in my head faster than you can set it up and do it with a calculator. If you travel 4.8 miles in 24 minutes (2/5 of an hour), then in 1/5 of an hour, you travel half as far or 2.4 miles. Then I multiplied 2.4 times 5 in my head and got 12. Can you do that? Sure. 5 times 2 is 10 and you know the answer is going to be more than 10 because there is still the 0.4 (of 2.4) to deal with. That eliminates answer B, 10, which leaves us with C because we eliminated the other answers earlier. However, let’s just go ahead and finish multiplying 2.4 times 5. We already have 2 times 5 is 10. Then .4 times 5 is 2. Adding 10 and 2 gets us 12. We are all done.
The other thing to learn from this question is there’s always going to be more than one way to do math questions on both the ACT and SAT. (I’ve pointed out three ways for this question.) You could have done this question by doing a standard set of math operations or you could have done it the Wizard’s way. Any way is fine as long as you get the right answer! There’s no “right way” to do it except for you should do it the quickest, easiest way that works for you. You’ll discover how to do math questions the most efficiently by practicing. So, get to work!
I hope you have a great week. This is AP exam week for many students. I wish you well with your exams.
Thanks for stopping by. I hope you’ll tell your friends about my blog and you’ll come back tomorrow.
Wizard
