PSAT 2010 Wednesday Math Discussion

<p>^^^
Oh ok, I didn’t realize you switch the coordinates when you reflect… -_- Thanks for clarifying.</p>

<p>agree that the answer is 5/7</p>

<p>but for the code, wouldnt it be 26x26x10 - 26? Because whenever you have AA and BB and so on the code is the same</p>

<p>what was the question for the trapezoid one, i dont remember a question about trapezoids</p>

<p>^I believe it was the 2 triangles and 2 rectangles in that one figure.</p>

<p>qwerty, you’re thinking too hard. You don’t have to subtract 26</p>

<p>wasn’t the answer 25, two or three people said it was 21</p>

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<p>I don’t think that’s how this problem works?</p>

<p>Pretty sure it’s just 26 options per letter spot and 10 for the number spot (26<em>26</em>10).</p>

<p>find the area of a trapazoid; to do so you had to break it down into two congruent triangles, each with an are of 7.5, then there was also a rectangle with an area of 10, so the answer was 25</p>

<p>Although I may be mistaken about the answer apparently?</p>

<p>Yes but the code AA7 is the same as the code AA7 with the A’s reversed</p>

<p>it asked for how many different combinations there could be, and those are the same?</p>

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<p>There was no reversal of the letters? It was simply any letter in the first spot, any letter in the second spot, and any digit in the third spot. I don’t think AA7 was ever counted twice to begin with.</p>

<p>You only get one aa combination…no doubles</p>

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<p>To generate a code, you pick the first letter, then the second letter, and finally the number. Unless you can come up with two different ways to generate the code ‘AA7’ by that process, you don’t need to subtract anything from your answer, because there will be no duplicates—every unique code-generating process will produce a unique answer, i.e. an answer that is not produced by any different code-generating process.</p>

<p>ok I finally get it now, I wrote out all the combinations for A and theres no doubles, whew.</p>

<p>25 was the answer to another question the one with like two right triangles and a rectangle</p>

<p>21 was the shaded trapezoid on the cartesian plane of the linear line</p>

<p>^ how was it solved, i still dont remember the question</p>

<p>25: 3 times 5 divided by two multiplied by 2 equals 15.</p>

<p>2 times 5 equals ten.</p>

<p>Addition.</p>

<p>21: 3 times 4 equals 12.</p>

<p>3 times 6 divided by 2 equals 9.</p>

<p>Addition.</p>

<p>the question about the antifreeze -20 was 20% right because I didnt think it was too difficult but i saw someone say it was 40%</p>

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<p>It was 40%, unless I missed it too…</p>

<p>I as well got 40% and If I am wrong I quit life.</p>

<p>What was the one with like yrootsomething=xsquared or something. I guessed 1 but had nooooo idea. I think it was at the end of the 1st math…</p>

<p>I’m pretty sure 20 was the area of ABCD, if that hasn’t been discussed yet.</p>

<p>SAT Math > ACT Math. I totally blanked on 30-60-90 triangles and actually used the reference.</p>