<p>I found that formula (Avg. speed = (2<em>Speed1</em>Speed2)/(Speed1+Speed2) in Gruber's New SAT Guide (for 2005).</p>
<p>"And how many other valuable formulas, tips, methods, etc. are buried deep inside that mountain?</p>
<p>One has to maintain daily presence on this forum for months in order to accumulate knowledge that could be offered in a few tutoring sessions."</p>
<p>I agree, but there is no guarantee that the tutoring sessions would include many valuable tips or methods. I cannot make generalizations but I do not believe that the formula in reference is daily fodder at Kaplan, PR, or Sylvan. While I am certain that the formula or some variations have appeared in many books, I do not recall having seen in any of the common books for the SAT. Actually, I have seen different or incorrect approaches in PR and Rocket Review. It is obviously unfair to draw conclusions based on a single example. </p>
<p>As I said many times, there are no real secrets! </p>
<p>PS To maximize the benefit of this forum, students need to be proactive. It is true that information gets buried. However, few questions that are posed ever remain unanswered. There is usually someone who can point to the past. :)</p>
<p>So that this post by Xiggi doesn't get buried in the other threads, An</a> example of developing one's own "tricks"</p>
<p>eh that formula is essentially just a manifestation of exactly what vtran did. unless you're not confident in math i would spend the time memorizing words instead of formulas that prolly wont even come up</p>
<p>I'm going to play the retard. I don't get the formula. I thought itwas just
2(speed1)(speed2) / (speed1+speed2)</p>
<p>How come all those have T variables? How come they keep explaining it with d=rt. I thought Xiggi said that the formula works all the time. I'm very confused now.</p>
<p>And do you use it for avg. speed or how many miles were driven?</p>
<p>That formula only works for when the person goes the same distance 2 times, with different speeds for each trip. (For example going to and from work). It find the average speed for the 2 trips. The only time it finds the total distance is when the problem says the total travel time is 1 hour.</p>
<p>QJ, the problem usually shows up in the form of a MC such as the one posted by VT. Also, it usually tells you that the trip took ONE hour. As a result if the average speed for ONE hour is the same number for the distance (as in 12 miles per hour or 12 miles). That is why it is important to watch for that small but important detail. </p>
<p>A girl rides her bicycle to school at an average speed of 8 mph. She returns to her house using the same route at an average speed of 12 mph. If the round trip took 1 hour, how many miles is the round trip.</p>
<p>A. 8
B. 9 3/5
C. 10
D. 11 1/5
E. 12</p>
<p>Apply the formula for the average speed => 2 * 8 * 12 / 8 + 12 or 192/200 or 9.6 or 9 3/5. So in this case, the girl rode her bicycle for 1 one at an average speed of 9 miles for ONE hour, so she rode a distance of 9.35 miles total. That is all you need. There is no glory whatsover in playing with the d=rt formula. Sorry VT.</p>
<p>Also, a small addendum for Princeton who does not like to memorize a formula: if this problem shows up in a multiple choice, you do not need to even lift your pencil, except to mark B. </p>
<p>There three excludable answers 8 and 12 for obvious reason. The trap answer (chosen by a majority of students) that is 10. That leaves only 9 3/5 and 11 1/5. Well, the answer is ALWAYS slightly below the staright average of 10. If there is only ONE number between the staright average of 10 and the lowest speed, just mark it and move on. :)</p>
<p>Flipsta, it is true that one still needs to check the variables of the problem. But it is pretty simple to check if the question asks for the round trip distance or for the one-way distance, or another variable.</p>
<p>
[quote]
Esther drove to work in the morning at an average of 45 miles per hour. She returned home in the evening along the same route and averaged 30 miles per hour. If Esther spent a total of one hour commuting to and from work, how many miles did Esther drive in the morning?
[/quote]
so the forumla is actually T(sp1*sp2)/sp1+sp2? </p>
<p>And for MC, I avg. the two speeds together and its alwys the one that's slightly below?</p>
<p>
[quote]
</p>
<p>Sigh
As I have posted countless times on CC, this type problem is only difficult on the surface. It only requires a bit of attention to the problem statement, a bit of logic, and the use of a simple formula that should be in everyone's SAT repertoire.</p>
<p>One of the big problems is that our good friends at the PR and Kaplan of the world, as well as arrogant and pretentious authors such as Adam Robinson (from the error filled RocketReview SAT book) and Bill Drucker, prefer to unload a healthy dose of balderdash, flimflam, and tomfoolery onto hordes of poor students who are told NOT to trust their capabilities. Those "experts" send their readers in a tailspin of doubt with half-baked theories of finding the common denominators that require lengthy calculations, or even worse in a solution that ends up with a wild guess between two answers. They'll give easy examples that are supposed to work. I have little doubt that they would not be able to solve their own problems if the speeds happened to be 23 and 27, as opposed to the nice round numbers of 30 and 20.</p>
<p>Okies, off my soapbox for a few ... seconds. The reality is that this problem only requires you to know the formula for average speeds and pay attention to the problem statement.</p>
<p>How long SHOULD it take me to solve this problem?</p>
<p>Start your stopwatch.</p>
<p>Calculate (2<em>30</em>45)/(30+45) => 2700/75 equals 36.
Now I have the average speed of 36 mph for one hour of travel. Since the distance IS the same both ways (duh), the distance is 36/2 or 18 miles.
[/quote]
Is what you put for this problem, though. Is it T or 2? Because I know I would not remember to divide or whatever after the formula.</p>
<p>QJ, I am not sure where that T came from. </p>
<p>The formula REALLY uses the number 2 and not T. I could explain in details why the number 2 is in the formula, but I would be afraid to confuse you even more. The simplest way to explain is that there are TWO equal sections (back and forth).</p>
<p>QF, I found the "other" post where the same question was discussed. Since the question was asking for the ONE-WAY distance, an alternative solution was to isolate T in the calculations and calculate the DISTANCE at once. However, it does NOT change the formula for the average speed which is Average Speed = 2 * (speed 1 * speed 2) / (speed 1 + speed 2). </p>
<p>Notice that this formula is different as it is for the single distance and NOT for the average speed:</p>
<p>t[(r1r2)/(r2 + r1)] = d </p>
<p>It is important to read the problem and pay attention to the variables. The problems are solved with the same methodology but but can phrased differently.</p>
<p>Then how come your formula worked for that one about the lady who drove 30mph and then 45 mph and it asked for the distance? Did you mean to use 2 or was it just because it took 2 hours (I cant remember if it did or not)?</p>
<p>Quitejaded, you have to pay closer attention to the earlier posts. I sense that you are trying to plug in a formula without really understanding what it means. </p>
<p>In this kind of problems, there will always be relationships between distance, time, and rate (speed). For this reason, you can solve the same problem with different approaches. Do not jump from one approach to another, as you will go in circles. </p>
<p>Let's look at my response the post you just quoted. "Calculate (2<em>30</em>45)/(30+45) => 2700/75 equals 36. Now I have the average speed of 36 mph for one hour of travel. Since the distance IS the same both ways (duh), the distance is 36/2 or 18 miles." </p>
<p>I applied the formula I like and that is the formula for THE AVERAGE SPEED. As I wrote, we have the average speed of 36 MILES PER HOUR. That means that in ONE HOUR Esther will ride a distance of 36 miles. However, in hour she does the round trip. The question here asks for the distance for one leg. Since the total distance is obviously twice as long as one leg, the distance is one half of 36 or 18. </p>
<p>I would also suggest that you review the simple relationships of distance, rate or speed, and time . </p>
<ol>
<li><p>d = tr means distance = time * rate. Think, "How far do I go if I ride 1 hour at 36 miles per hour?" 36 miles = 1 hour * 36 m/h </p></li>
<li><p>t = d/r or time = distance / rate. Think, "How long do I ride if I complete 36 miles at 36 miles per hour?" 1 hour = 36 miles / (36 miles/hour) </p></li>
<li><p>r = d/t or rate = distance / time. Think, "What is my speed if I complete 36 miles in 1 hour?' 36 mph = 36 miles / h. </p></li>
</ol>
<p>It is very important to know the basic relations because you always need 2 elements to find the third and missing one.</p>
<p>xiggi, can you please give us some examples related to CR? Thanks</p>
<p>Well, this is for SAT preparation...for those of you who care...I'm not trying to be Xiggi here but, just a thought.</p>
<p>Anyway, I would reccomend the following as a MUST to raise your SAT score significantly:</p>
<p>SAT: OFFICIAL STUDY GUIDE ************* A MUST!!! contains 8 practice tests ACTUALLY made by collegeboard. A realistic level compared to the real thing, unlike all of the PR or Kaplan books (admit it, even if you are a fan)</p>
<p>Some Kaplan or PR books, to give you extra practice tests...</p>
<p>ROCKET REVOLUTION: NEW SAT...or something like that. This book is the best!!! it literally defies against all common sense and everything we have ever learned, BUT it W O R K S !!!</p>
<p>Also, Rocketreview is written in a very friendly manner...so that anyone reading is not bored with the PR style of writing. PLUS it's a big book so it provides enough review for the best improvement. BUT the best thing comes for all of you who are biting your nails about the essay. With the book, you get a CD- rom...that gives you access to this website that has the following...
ROCKETSCORE: a fascinating tools that uses algorithims and previous human-graded essays and artificial intelligence to ACTUALLY grade an essay. It really works, it's not just a spell-checker.
Omniproctor: a way to simulate test conditions when you take your practice tests...check it out for yourself.
ADAM: no that's not an abbreviation, it's a person. Adam Robinson (also the author of the book) is a very friendly and extremely devoted man, who in return answers any questions and can even GRADE your essays!!!</p>
<p>Anyway...rocketreview is great...it exposes some hidden ideas that no other books have ever shown...like which questions you should spend the least amount of time (the difficult ones is the answer), that quantity is usually more important on the essay than quality...and NUMEROUS other strategies that i cannot even begin to list. Adam sees a practical view, also the author of CRACKING THE SAT (ever heard of it, it was on the NY Times bestseller list!). </p>
<p>So, get the blue book (SAT official guide), the green book (maybe a kaplan book) and definitely the red book (rocketreview)</p>
<p>AND THEN YOU NEED THE MOST IMPORTANT THING OF ALL</p>
<p>your dedication....it really helps trust me...</p>
<p>Now that you have read this extremely long post, i will decide to end it now...now and then, i may pop up with additional info like this one...but i'm done for now.</p>
<p>WHEW! that was a lot of typing!</p>
<p>Have a nice day!</p>
<p>HEY XIGGI IS THIS THE THREAD YOU WERE TALKING ABOUT ON THE 1ST PAGE?</p>
<p>"First off, let me assured you that there are no earth-shattering secrets in what has been -very generously- dubbed as the Xiggi method. I think that it is mostly based on common sense. After all, how hard is it for anyone to figure out that the more one practices, the more one improves. However, there are a few elements that seem to work better than others. Also, I may be able to point to certain elements of a preparation that yield lesser results. For instance, I do not recommend to spend MUCH time reading lists of words.
I'll try to get something posted this afternoon. I'll address one question immediately: taking tests under timed conditions." </p>
<p>"The answer is yes but only at the end of the preparation, and eventually at the onset if you did not take an official test. In the past I have compared an SAT preparation to the preparation for a marathon. It is not necessary to run 26 miles each day to prepare for a race. It is better to prepare your body for the grueling race in smaller installments and build resistance and speed by repetition. I do not think that there is ANYTHING wrong in trying to emulate the testing conditions by setting aside a few Saturdays at the kitchen table. It is, however, not necessary, especially in the phase where you build knowledge, confidence, and time management. I would recommend 10 installments of 30 minutes over taking an 5 hours ordeal. One of the keys of a successful preparation is to establish a number of intermediary targets. First, you want to make sure you understand the test and its arcane language. Then, you want to test your current knowledge. After that, you want to make sure you understand what TCB considers correct answers. As I will post this afternoon, I even recommend taking a test WITH the answers in front of you. Obviously that test would not establish a valid yardstick score wise, but it will go a long way to build confidence in your own ability and recognize the few traps that ETS uses."</p>
<p>I don't know if this is the right spot to ask Xiggi this question, but I am afraid it will go unnoticed on the barron's practice tests thread.
Xiggi, there are only two SAT II math tests (one IC and one IIC) in CB SAT II book.
Where can we get true SAT II math tests? Has CB ever released real SATII tests thru Q'n'A service?
What do you think of Meylani SATII math tests books? People swear by them on amazon.</p>
<p>Hi. About the xiggi method: For the first practice tests I take in the collegeboard blue book, would it be a good idea to use a dictionary for the non-passage parts of the verbal sections (even though it would actually give me the "answers"?
Thanks.</p>
<p>Sentence Completion? No, it would become ridiculously easy... it would be a good idea, however, to look at the words you dont know before taking the test, learn them, and then do the test and see how much you know.</p>
<p>Couple of answers. </p>
<ol>
<li>As far as I know, the only official SAT-II Math tests released by TCB ar ein the books. I never heard them sell any. One place to check is ETS. They do sell tets such as past editions of the PSAT and seem to change their mind easily. </li>
</ol>
<p>In the meantime, the tests of Meylany offer one of the best substitutes, despite being a tad harder. </p>
<p>While for the SAT Reasoning there is absolutely no reason to waste time with synthetic tests, the same cannot be said for Subject tests because so few official tests have ever been released. </p>
<ol>
<li>The purpose of using books and ... answer keys during the first practice tests is to increase your awareness of the way ETS develops its questions. The score is not important and there is nothing wrong to look up the words while answering. While I would suggest to spend a bit of time looking at the problem before jumping to the dictionary, the result is the same. The key is to try to UNDERSTAND how the test works, to see WHY a minimum of TWO answers will be OBVIOUS bad choices, and why there is only ONE correct answer. Knowing the correct answer allows a student to uncover the relationships between the problem and answer choices.<br></li>
</ol>
<p>While checking the words, make sure to spend time recognizing the roots, prefixes or suffixes. </p>
<p>Good luck.</p>