June 2010 Math

<p>Yeah it was 6, what about the one with (n+2)? I put E: (n+2)(n+3)/2</p>

<p>What did people get for the one with how many chairs were removed… trying to remember what I said but can’t… pretty sure I got it right</p>

<p>I got 22 for the chair one.</p>

<p>I V, it was 24</p>

<p>AirforcePilot, I concur. My precalc class just finished sequences and series and your answer for the n+2 one is correct.</p>

<p>I got 24 as well. I think.</p>

<p>10+12=22 chairs
since they removed a whole row columns became 5 each</p>

<p>for the 3 square root 2 question… no it was 3 square root 3, because it was a 30-60-90 triangle with sides 3 and 3 so the hypotoneuse was 3 root 3</p>

<p>Was #19 the 20 question one just 1 or 1 and 2.</p>

<p>also it was not 24 it was 22</p>

<p>10 + 6 + 6 or 12 + 6 +6 -2</p>

<p>Science, I agree it was 22. Not 24 because the row was removed BEFORE the columns, making each of the two columns have 5 chairs. 12 + (5*2) = 22.</p>

<p>Air and golfer - how did you get 24?</p>

<p>For the c/a ratio (it was like 9/a …) did people get 1/3? I believe it was the 1st or 2nd SA.</p>

<p>u just use similar triangle for the 3 sqr whatever
one triangle is 3 by 3 by hypotenuse the other was 9 by 9 by hyp.
3^2+3^2=18
sqr 18=3sqr 2</p>

<p>So there were 6 rows and 12 columns (12 chairs in a row, 6 in a column). They removed one row of chairs, so now the rectangle of chairs is 5 by 12. Then they removed 2 columns of chairs, so now the rectangle is 5 by 10. So it goes from 72 chairs to 50 chairs, and they remove 22.</p>

<p>For the triangle one I found out that the triangle contained within the square had a 9sqrt2 hypotenuse and the whole triangle had a hypotenuse of 12sqrt2, so subtract them to find the length of the hypotenuse outside of the square, and you get 3sqrt2</p>

<p>Also, for the sequence one, which was I believe just a1=3 r=3; a sub n = (3)(3)^n-1 = 3^n… NO numbers in between 100 and 200… since it would go 81 to 243?</p>

<p>Also wondering if people got 1/3 for the ratio.</p>

<p>Whoops, careless mistake haha. Didn’t look at it from the rectangle perspective, just subtracted 24…■■■</p>

<p>Judging from this thread, I had some pretty dumb mistakes and some really lucky guesses on the math…hoping for a 650+, though I definitely got at least 1 mc and 1 grid-in wrong already and skipped 5…:(</p>

<p>was the question for the 20 test scores</p>

<p>1 or 1 and 2 also please explain.</p>

<p>or just 9x9=81. 81x3=243.
none of that complicated stuff.</p>