<p>1) This morning in the qualifying rounds, Rusty averaged 180 seconds per lap until he began the last lap. He then went to a lower gear. He averaged 190 seconds per lap for this qualifying round. How many seconds did Rusty take to drive the final lap?</p>
<p>A. 155
B. 160
C. 185
D. 200
E. 260</p>
<p>Silly question. But then it is the ACT.</p>
<p>It takes ONE second to solve. It would take five more to explain why the solution is what it is.</p>
<p>are you sure this is even a real ACT maths question? this is really vague. first of all there is no specified number of laps to count, and second of all, it would take him 190 seconds to run the final lap if he ran 190secs/lap, wouldn’t it???</p>
<p>then what is the answer?</p>
<p>It is not vague and that is why it is so silly.</p>
<p>Fire lion, how many answers are larger than 190? And think about why 200 cannot be correct.</p>
<p>can anyone answer my question? the answer is 200 from 1296 PR act book</p>
<p>I may be misreading the problem, but it seems to me that it could be 200 or 260. 1 lap each at 180 and 200 averages 190. 7 laps at 180 and 1 at 260 averages 190. If the problem is implying more than 1 lap at 180, answer should be 260. But that is not explicitly stated, poorly posed.</p>
<p>Again, it is a silly question and the answer cannot be 200. If this come from PR, it is only one more exhibit of why NOBODY should use that garbage. </p>
<p>To be clear, the answer cannot be 200 because that would mean only a TWO lap race. One at 180 and one at 200. Since the question included that the previous laps averaged 180, there are more than one. You need at least TWO elements to have an…average.</p>
<p>The answer is 260. And it is the only one that works. Again, it would take a SAT tester just a second to SOLVE that … Through mere reasoning. But since the ACT is a plug and chuck test, here is how you can solve the problem in five more seconds.</p>
<p>Your paper should show this:</p>
<h2>18 - 19 - 26</h2>
<p>----1----7—</p>
<p>That means SEVEN laps at 180 and ONE lap at 260. And the EIGHT laps average 190.</p>
<p>Dumbest problem I remember reading. It would be level ONE on the SAT.</p>
<p>N =1 is the degenerate case of arithmetic mean, not really useful. But I can’t find a definition that specifies n MUST be greater than 1. I always tend to think you have to account for every case when problem statement is vague. But on a test I would absolutely choose 260 if I have to make a choice and can’t argue with test writer about language. Do you know of a good math dictionary?</p>
<p>@ Xiggi, </p>
<p>I felt SAT Math was easier than ACT’s. But that might be because I had a sinus infection and was suffering greatly during the math portion on the ACT (750 SAT M, 31 ACT M)</p>
<p>I’m pretty sure the arithmetic mean is still defined for n=1 (AM-GM still holds). In this case, the answer could be 200 or 260. I agree with everyone else, regardless of whether 200 or 260 is correct, this question is completely useless.</p>
<p>Defining the average of one number is just as useful as trying it when n is zero. </p>
<p>This is not about some high level mathematical definitions but about 9th grade reasoning.</p>
<p>easy xiggi. </p>
<p>Middle schools do not teach reasoning. Some kids are born with the reasoning DNA. Others need to act like they want to go to Carnegie Hall (practice, practice, practice).</p>
<p>IMO, the lack of reasoning skills is why Organic Chem is such a bear and the bane of most premeds. It requires reasoning under time pressure, (just like the SAT). For those with the reasoning gene, and fast math processing, organic is fun. For others, its a huge struggle, and given the mandatory curve…</p>
<p>Many kids finally do “get it” in the second semester, and then raise that low C to a B or low B to an A. But, IMO, what they are finally “getting” is the ability to reason rapidly, not organic per se.</p>
<p>I do not disagree. Reasoning, however, is also a result of using the practice sessions well. </p>
<p>Perhaps, I should replace the term reasoning with simpler terms such as thinking or common sense. :)</p>
<p>The arithmetic mean of one number is just the number itself. Analogous to, the determinant of a 1x1 matrix is the number itself.</p>
<p>Regardless, the question is poorly written and shouldn’t be used (I’ve seen worse from other test prep companies though).</p>
<p>
</p>
<p>And why I called it as useful as finding the average of … zero numbers. Perhaps there is a use to define or determine the average of ONE number in some arcane and abstract high level mathematics, but such definition strays far from the common application of the average being … well, the average of a series of values. </p>
<p>Back to the original problem, it is blatantly obvious that the earlier lapS did average 180 and that there were more than 1. If there was only one lap, the question would have been written differently. </p>
<p>And it is obvious that the correct answer of 260 was not an accident. If the answer provided by the book is indeed 200, it is a result of the typical shoddy editing of the publishers.</p>
<p>I wonder if they would put something like this on a real test, since they ask for BEST answer and one answer is clearly better than the other. One should know that the commonsense answer beats the technically correct but somewhat nonsensical answer. Or would college board discard as being too close to having 2 equally good answers so that people would appeal scores after the test.</p>
<p>You should contact Princeton Review to tell them so they remove from future editions. And complain about the brain ache you got reading this thread so maybe they’ll send you a coupon for a free smoothie</p>
<p>^^</p>
<p>In theory, and without going into details, this should never happen on the SAT Test because of the system they use to incorporate new questions. In the recent history of the SAT, I believe that there have been a few cases where a question might have been tossed out because the reaction to the entire community of testers was different from the reaction of the experimental testers. In general, however, ETS has a stellar record in providing clear, precise, and relevant questions. </p>
<p>As far as I know, the only question that have seen on a real test that was “vague” was the one about the surface of a cube versus the surface of one side. </p>
<p>As far as contacting PR for a smoothie, I am afraid that this would be a lost cause. The publishers of synthetic tests have shown little to interest in correcting the mistakes as they keep appearing in subsequent editions. I have come to the conclusion that they might not even understand why the question (and its answer) is wrong or misleading. </p>
<p>But, thank you for the sarcasm!</p>