@ADITYAEMPIRE @chessmaster1077 wait don’t they have a computer science course or smth lol that’s my level of lazy
they got algorithms @JumpyJLizard and java programming i think lol
most amc problems you don’t really need ‘original thinking’, its just reusing and reapplying existing knowledge to convert the problem into an already solvable problem, then solving it.
@chessmaster1077 yeah lol i’m saying unoriginal problem writing. MAA paints more interesting scenes
so the question was somth like
A man walks d miles at a constant rate r. If he walks 1/2 miles faster then he walks the distance in 4/5 t. If he goes 1/2 slower then he walks the distance in t + 2.5 hours. Find the distance.
I set up three system of equations to find 3 variables; d,t,r. r = 2, t = 15/2
d = rt
d = (r+0.5)(4t/5)
d = (r-0.5)(t+2.5)
From the first two, it can be deduced that r is 2. (r+0.5)(4t/5) = rt
t(4r + 2)/5 = rt
(4r + 2)/5 = r
4r + 2 = 5r
2 = r
d = 2t (sweet)
Let’s use the next one to find the time.
d = (2-0.5)(t+2.5)
d = 1.5t + 3.75
2t = 1.5t + 3.75
0.5t = 3.75
t = 7.5 or 15/2
15/2 * 2 denom’s cancel giving 15 as the final answer. Notice how I made the problem easier by not setting the bottom two equations equal to each other. You have to be smart about the method you choose, as that will save you time on the test. Unfortunately for tests like these, it’s not really how you solve it, but how fast you can solve them.
@chessmaster1077 yeah i agree
i basically did it the same way, but i’m kinda bad with rate problems so i just did it based on how the sentences said it
d/(r+1/2) = (4/5)(d/r)
and the ds cancel and you get r=2 after cross-multiplying
d/(r - 1/2) = d/r + 5/2
and then you know r = 2 so
d/1.5 = (d+5)/2
so d = 15
also definitely true, especially for the first math part with the average rate of problems completed being one per 48 seconds i cri ;-;
you did it in a much better way than i did @JumpyJLizard
the first math was terrible i found the first 30 so easy i took a little nap and woke up seeing the 10 minute being crossed out. had i known that time would pass so quickly i would not have taken a nap lmao
@chessmaster1077 hmm possibly but thanks
I mean the nap wasn’t uncalled for lol
the science section was probably my worst part though; guess who didn’t study acids and bases as well as they should have
what did you guys get for the person with the cabbage juice and the question with answer choices:
a) several portions of 0.1M HCl
b) several portions of distilled water
c) several portions of NaCl
d) a solution of HCl, a solution of NaCl, and a solution of NaOH
(or smth like that)
also like for the definition of an acid one, which one was it?
a) dissolves in water
b) reacts with bases
c) ionizes completely
d) tastes sour (lol ima taste some HCl want some?)
also the earth sci one about the granite dike
a) formation of bottom limestone layer
b) wavy line indicated by ‘I’
c) some weird curve thing they mentioned
d) crystallization of schist
also the physics question about the graphs of the variable that was directly related to I (amps) looked the same way as the original graph right?
usually i would search them up, but these are kinda vague/vary with the problem specs
the physics one is direct im pretty sure yeah
the other ones i skipped i legit had no clue
Goodluck on the exam. I’ve heard it is hard from a friend.
the cabbage juice one was d i’m pretty sure. For the acid one i’m pretty sure its react with all bases. That question is weird because as a general physical trait acids do tend to taste sour, but I doubt thats the answer. And i’m pretty sure acids don’t ionize completely cause weak acids and stuff. Idk any earth science so I don’t know that question.
thanks
i kinda unintelligently (is that a word?) guessed those as A, B, and B even though they were only guesses on a whim
which is why i was asking about how detrimental wrong answers would be to your score
like -1/2 for each one? -1? does anyone who has taken it before remember if guessing took a large toll on their score?
^ (it is a word)
i dont think you get your scores back, i heard from someone its +3 for correct -1 for wrong and 0 for incomplete, kinda like old SAT
@futurebruin205 thanks
@OsamaCare it’s sad because i was thinking that when it depends on H+ concentration (instead of presence) it might be nice to see if the different amounts of hydrochloric acid solutions gave small changes in color, but i also considered D at the beginning too ;-; feels bad
@chessmaster1077 thanks, i hope that the ones that i guessed were at least half as many right as wrong then :))
From the answers discussed, a more accurate score for my science section would probably be 68-70. oof 
@chessmaster1077 that sounds about right.
Thank you so much JumpyJLizard! You’re a lifesaver.
omg im banking on that froshling curve so hard lol
@JumpyJLizard
Your method of reasoning for solving the line tangent to the circle problem was excellent. I used a more algebraic way.
I found the point of tangency by using substitutions. I realized that the line perpendicular to y = - x + r is just y = x because the circle is centered at the origin (x^2 + y^2 = r). Setting these two equal to find the intersection yields x = - x + r. Or r = 2x.
Substituting this into x^2 + y^2 = r gives x^2 + y^2 = 2x.
Remember that y = x ( plug 2r in to x if you don’t believe)
2x^2 = 2x
2x^2 - 2x = 0
2x(x-1) = 0
Sol is 0 and 1. 0 makes no sense so x is 1. Remember r = 2x
R is 2
Does anyone remember the base question and what it was
@56Student2022 no problem
@ADITYAEMPIRE same
@CSGO2022 thanks! your solution was more rigorous though haha
the base question was something like:
the girl bought something for 440, gave the cashier 1000 and got 340 back as change
what base number system are they using?