<p>did anyone get the probability one with the perfect squares? i got a number that i had to round to match one of the answers</p>
<p>yeah, 16/3 was one of the answers. i know cuz if you plugged in 1.5 as x, the answer was higher than 5, so that only left 16/3 as the only possible choice.</p>
<p>@whichever post said 11 was the cut off:
People who do pretty well on challenge math usually do well on other sections as well</p>
<p>For me,
49/50 on easy math, 60-65ish on the science, 14/15 challenge math;
Chances?</p>
<p>@daniel6738</p>
<p>i got 0 for that question does anyone remember it if so give ur awnser</p>
<p>what is the maximum value of 8x-3x^2</p>
<p>^The maximum value was 16/3?</p>
<p>@pokemonwhite: I think this year’s cutoff on challenge math is probably around 12. Just my opinion, so don’t freak out anyone</p>
<p>ok can someone explain how or why they got 16/3 because when i plug it iinto calculater i get a negative number</p>
<p>and does anyone know the answer for the one with with the absolute values as denominators? like a/|a| + b/|b|…</p>
<p>It was like 8x-3x^2 so you have y=-3x^2+8x, a quadratic equation that’s an upside down parabola. The vertex is the highest point. x value of it is -b/2a or 4/3. Plug that back in to get the y-value, the maximum.</p>
<p>You could use a calculator?</p>
<p>well, you’d be suprised…</p>
<p>My friend took it last year and he thought it was really easy (he never took the AMC 10 but im pretty sure he’d do well, seeing as he and i both made AIME for AMC 12 this year) but according to some teachers, not a lot of people got them right…</p>
<p>maybe it just seems that way because collegeconfidential kids actually study ^^</p>
<p>for the absolute values i got C which was -4,0,4</p>
<p>you solve for the vertex and then plug it in
vertex is -b/2a
so, - (8)/2(-3) = 8/6 = 4/3</p>
<p>Plugging that into 8x-3x^2,</p>
<p>8(4/3)-3(4/3)^2
32/3 - 3(16/9)
32/3 - 16/3
16/3</p>
<p>@ daniel6738</p>
<p>Im pretty sure it was the set [-4,-2,0,2,4] because they all turned out to be 1, -1, or 0 and you can get all the numbers that way</p>
<p>@masterofpupets. thats what i got but was that choice b or c?</p>
<p>The one with the absolute values was {-4, 0,4} because there were only certain combinations of negative & postives you could plug in, and they always resulted in those 3 numbers</p>
<p>i agree with master of puppets on the absolute value question was it 4, 0 , -4</p>
<p>Is this the same test as on 4/02? Just curious</p>
<p>does anyone remember any of the science questions? guessed on alot of physics :/</p>
<p>oh wait, it was choice b lol</p>
<p>ohh ok yay thats what i got then :)</p>