EPTSAT Math Question - Page 2
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lilpwnyIII
United States23 Posts
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peidongyang
Canada2084 Posts
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oneofthem
Cayman Islands24199 Posts
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Klockan3
Sweden2866 Posts
On April 05 2009 03:15 Ecael wrote: Klockan, except SATs and such are not testing your mathematical abilities. If this was say, his final on a 9th grade math class, I'd tell him to use variables. Except this is a test where you are timed, tested for consistency, and need to be efficient. I don't see how wanting to learn math is relevant at all to this. That was exactly my point. And the relevance of someone's maths interest is that someone more interested in maths will most likely study maths later and as such he really needs to start think in variables since that is what higher maths is all about and the sooner the better and the small extra time it takes to understand such things is nothing if you are into it. | ||
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Divinek
Canada4045 Posts
why would it even seem like that? did you read the question? does that seem like a bad way to do it | ||
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benjammin
United States2728 Posts
so it can't be a, 4 white eggs / 6 brown eggs = 2/3, 4+6 = 10 | ||
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Cambium
United States16368 Posts
On April 05 2009 06:03 Divinek wrote: why would it even seem like that? did you read the question? does that seem like a bad way to do it Okay, tell me how it's not a better approach to use variables: There are 75 more women than men enrolled in Linden College. If there are n men enrolled, then in terms of n, what percent of those enrolled are men? To solve it using variables (which was given ffs): # of men: n # of women: n+75 % men = 100 * # men / [(total =) #men + #women] :. % men = 100 * n / (n + n + 75) To solve with numbers You have to derive the exact same expression with 25, and calculate a concrete percentage, then match this percentage with all the wrong ones in the answer. If you don't see why this is more time consuming and redundant, then I guess there is a reason why you think it's a better idea to use numbers. And also, if you know to use 25 (it's not magic btw), you've pretty much got the problem solved. Imagine if you used 1, or 15 even, solve by numbers wouldn't be so easy. By more error prone, I mean you have to type this number into a calculator multiple times, every time you type it, you are introducing potential errors. tl;dr version: Using numbers is the same as using variables except you have to perform the actual calculation. If you can solve the problem with numbers, how is it possible that you can't do it with variables?! Question 2: You are given a ratio of white vs. brown, you have to derive the expression of white vs. total or brown vs. total. You'll see that the total has five "shares", so that the total number of eggs must be a multiple of five. | ||
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Klockan3
Sweden2866 Posts
On April 05 2009 06:18 Cambium wrote: tl;dr version: Using numbers is the same as using variables except you have to perform the actual calculation. If you can solve the problem with numbers, how is it possible that you can't do it with variables?! If you know the formulas but can't derive them and don't understand them. Edit: Also it is a perfect way to check that your answer is actually correct. | ||
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Sadist
United States7328 Posts
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benjammin
United States2728 Posts
On April 05 2009 06:54 Sadist wrote: meh I dont like how they try to trick you on those standardized tests, Id have gotten 1 wrong because I didnt multiply by 100, and 2 is just gay i don't understand this, especially now the ability to do the type of math that is being tested isn't as much of a benchmark as it is to be able to think accurately about how to solve the problem, but i did well on the sat so i guess i'm biased :O | ||
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Kentor
United States5784 Posts
On April 05 2009 06:54 Sadist wrote: meh I dont like how they try to trick you on those standardized tests, Id have gotten 1 wrong because I didnt multiply by 100, and 2 is just gay i do. there are plenty of easy questions where there are no tricks. of course there should be some "hard" questions in there too.... can't be all easy. | ||
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Archaic
United States4024 Posts
On April 05 2009 05:11 lilpwnyIII wrote: pluggin in is a good strat for people that aren't too smart You're wrong. Plugging in is in itself faster than working with variables. It isn't a contest for people to prove how smart they are, it is a contest to get it *right*. Being right is all that matters. If plugging in lets you do it faster, then you better do it so when you finish earlier, you have more time to check over your answers. | ||
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Zherak
Norway256 Posts
On April 05 2009 06:18 Cambium wrote: Okay, tell me how it's not a better approach to use variables: There are 75 more women than men enrolled in Linden College. If there are n men enrolled, then in terms of n, what percent of those enrolled are men? To solve it using variables (which was given ffs): # of men: n # of women: n+75 % men = 100 * # men / [(total =) #men + #women] :. % men = 100 * n / (n + n + 75) To solve with numbers You have to derive the exact same expression with 25, and calculate a concrete percentage, then match this percentage with all the wrong ones in the answer. If you don't see why this is more time consuming and redundant, then I guess there is a reason why you think it's a better idea to use numbers. And also, if you know to use 25 (it's not magic btw), you've pretty much got the problem solved. Imagine if you used 1, or 15 even, solve by numbers wouldn't be so easy. By more error prone, I mean you have to type this number into a calculator multiple times, every time you type it, you are introducing potential errors. tl;dr version: Using numbers is the same as using variables except you have to perform the actual calculation. If you can solve the problem with numbers, how is it possible that you can't do it with variables?! Question 2: You are given a ratio of white vs. brown, you have to derive the expression of white vs. total or brown vs. total. You'll see that the total has five "shares", so that the total number of eggs must be a multiple of five. Of course solving with variables is great if you actually know the maths to do it right. But, seeing as he is actually asking these questions; he probably isn't all that comfortable with working with variables, and besides, it is easy to mess something up and get one of their intentionally-almost-correct answers. Solving with actual numbers is actually pretty damn good for these reasons. | ||
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Avidkeystamper
United States8556 Posts
On April 05 2009 08:02 Archaic wrote: You're wrong. Plugging in is in itself faster than working with variables. It isn't a contest for people to prove how smart they are, it is a contest to get it *right*. Being right is all that matters. If plugging in lets you do it faster, then you better do it so when you finish earlier, you have more time to check over your answers. Actually, since people in more advance math usually work with concepts and abstractions instead of concrete variables, they are used to working with variables and thus the plugging in method is faster for them. But it all depends on what you're comfortable with; the way you solve a SAT Math problem does not dictate your knowledge. | ||
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Person514cs
1004 Posts
(total = n + n + 75) B (total is multiple of 2+3 = 5) | ||
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PH
United States6173 Posts
I'm a philo major...my math requirement was an intro computer class where I learned how to use Word and Excel...lawl. | ||
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Klockan3
Sweden2866 Posts
On April 05 2009 08:43 Avidkeystamper wrote: Actually, since people in more advance math usually work with concepts and abstractions instead of concrete variables, they are used to working with variables and thus the plugging in method is faster for them. But it all depends on what you're comfortable with; the way you solve a SAT Math problem does not dictate your knowledge. I hope you meant that using variables is faster if you are experienced with maths, thing is that you can see the answer to the question instantly if you are and thus it is impossible to do it faster by plugging in random numbers... | ||
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fight_or_flight
United States3988 Posts
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uriel-
Singapore1867 Posts
I guess I can see the substitution option coming in handy to check or something, but I've been educated to work it out algebraically pretty much all the time >_> | ||
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IzzyCraft
United States4487 Posts
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