<p>How did every one do #15? I did A/B+1=0.2 and A+1/B+1=0.3333 and then solved for A/B, which is 23%</p>
<p>ok so i got r=2 , and i found JHUgirl we sat next to each other 
the pennies nickel w.e was like so there 5 of each and i think the cost was like 2.73 , so uhh i forgot what i did but i think i got that problem UGH that question with Al and Bob and their ages -____- i think i did alright on the challenge math , like 10/15ish i hope and the science like some of them were super easy and others were just like what ? i should have reviewed physics so im guessing like a 60/75 , and UGH the easy math was easyish some questions were straightforward but some questions look a longer time than others and i left some blank thinking i would have time to go over it but i didn’t ): … oh well columbia seemed like an amazing place i really want to get it but if i dont then ill try next year (im a freshman ) (:</p>
<p>The age was 102, just set up an equation, pretty easy, but what about the last one???</p>
<p>i tried to set up an equation somehting like this A= 16+B_+C and then A^2=1632 + (B+C)^2 , that was the equatuion right ? im pretty sure but then i got confused and i was tired and hungry and my brain was fried and i was too lazy to concentrate ):</p>
<p>The last question was definitely 25%. If you assume that the original solution contained three ounces of water and 1 ounce of acid, or 25% acid, adding 1 ounce of water would lower the percentage of acid to 20%, since there would be five total ounces of solution at that point. If you then add another ounce of acid then there is six total ounces of solution, two of them being acid, yielding 33 and 1/3 % acid.</p>
<p>anyone about #15???</p>
<p>I I think it was 25 also, that means I got 9/15 I think that’s good enough to get in :)</p>
<p>Oh well, but is 12 challenge good enough???</p>
<p>what did everyone get for the question for the maximum value for 8x-3x^2?</p>
<p>@JHUgirl i tried looking you up on facebook but i can’t find you ):</p>
<p>maximum value 13/6, ( is 12 challenge math enough for a sophmore???)</p>
<p>either my memory is bad or I never saw that answer on my test was it 8/3</p>
<p>I think it was 16/3, ciz I remember getting 32/6</p>
<p>SHOOT was the coins answer really 18? i put 3… ugh did i read the question wrong :</p>
<p>One last question, if I got 12 challenge right and did 50/50 easy math, pretty darn good on science, can I definetely get in???</p>
<p>anyone???</p>
<p>so i’m a junior. it was the first time i knew about the program and the only chance i could try.</p>
<p>i got like 46/50 for easy math, 40/75 for science (because i only learned chem and physics. i know nothing about bio and earth science or whatever you call it), and 12-13/15 for challenging math. im not familiar with yard/foot and ounce units. all i have been using in my life is meters/centimeters and milliliters, which are all 10-based units.</p>
<p>to be honest, the challenge part was far more easy than i had anticipated, and the problems were nothing like AMC 12 as claimed by some on this thread.</p>
<p>werd. I studied a lot of discrete math and it only came in handy for that intersection set question on the easy section lol</p>
<p>I actually didn’t know yards neither! Why do they even put that on the test! I did really well on science and 12 on challenge</p>
<p>yeah the questions were nothing like the amc 12. for the maximum one</p>
<p>all you had to was take the derivative, use a sign chart to verify it was a max and then plug it into the equation.</p>