[VIDEO] greenturtle3141 takes the 2021 Fall AMC 12 B

by greenturtle3141, Dec 18, 2021, 8:14 PM

https://www.youtube.com/watch?v=0Uyo3k_MVU4

lol i got a 103.5 somehow, that's a record low for me :p

Thoughts:
  • i still have no clue how to do Problem 5 pls help
  • Problem 8 was... oddly difficult. Could have been a #16. Am I missing something?
  • Problem 14 felt dumb.
  • No clue how to do 16.
  • Problem 19 felt extremely misplaced; could have been a #12.
  • Problem 20 was slightly misplaced.
  • Problem 23 was not good: Either you know the method or you don't. And if you do know the method, it's #10 difficulty.
  • Overall, a very odd AMC. I'd expect a lower cutoff.

Comment

5 Comments

The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
yea #5 was really misplaced, the only method is to bash out the possibilities. you first list the fractions as
1/14
2/13
3/12 --> 1/4 (*)
4/11
5/10 --> 1/2 (*)
6/9 --> 2/3 (*)
7/8
8/7
9/6 --> 3/2 (*)
10/5 --> 2 (*)
11/4 (*)
12/3 --> 4 (*)
13/2 (*)
14/1 --> 14 (*)
All fractions of interest are denoted with an asterisk. Then you group the fractions by similar denominators

(1/4,11/4) The only possible sum here is 1/4+11/4 = 3.

(1/2,3/2,13/2) We can double each fraction to get 1,3,13. When we add two fractions out of three from this set, we get 2,7,8.

(2,4,14) We double each to get 4,8,28. We then add two distinct whole numbers to get 6,16,18.

Our list of fractions is now 3,1,3,13,2,7,8,4,8,28,6,16,18. But we have counted 3 and 8 twice, so our actual list with no repeats is 1,3,13,2,7,8,4,28,6,16,18, giving us 11 total possibilities.

by SuperCJ, Dec 18, 2021, 10:44 PM

The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
yeah i feel like Bs tend to be pretty misplaced

uh 5 was just bash

16 was also bash ("oh this is probably going to be too small" etc) :laugh:

by depsilon0, Dec 19, 2021, 6:36 AM

The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
p5 should've been p15 haha - really tough and bashy. you have to list all fractions knock out the ones you know won't work and then basically bash cases tbh.

yeah expecting lower cutoff too; is 94.5 safe?

by OlympusHero, Dec 19, 2021, 10:26 PM

The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
Well, glad to know I'm not crazy and 5 is just odd :p

@OlympusHero Hmm I don't consider myself much of a cutoffs expert, but judging by past cutoffs I do think that your odds are good. It seems like cutoff for 12A/B is rarely ever greater than 94.5, and I don't think that this test was historically easy.

by greenturtle3141, Dec 19, 2021, 11:34 PM

The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
apparently it was rly hard lol

by v4913, Dec 27, 2021, 2:16 PM

Turtle math!

avatar

greenturtle3141
Archives
+ October 2024
Shouts
Submit
  • Can you give some thought to dropping a guide to STS? Just like how you presented your research (in your paper), what your essays were about, etc. Also cool blog!

    by Shreyasharma, Mar 13, 2025, 7:03 PM

  • this is so good

    by purpledonutdragon, Mar 4, 2025, 2:05 PM

  • orz usamts grader

    by Lhaj3, Jan 23, 2025, 7:43 PM

  • Entertaining blog

    by eduD_looC, Dec 31, 2024, 8:57 PM

  • wow really cool stuff

    by kingu, Dec 4, 2024, 1:02 AM

  • Although I had a decent college essay, this isn't really my specialty so I don't really have anything useful to say that isn't already available online.

    by greenturtle3141, Nov 3, 2024, 7:25 PM

  • Could you also make a blog post about college essay writing :skull:

    by Shreyasharma, Nov 2, 2024, 9:04 PM

  • what gold

    by peace09, Oct 15, 2024, 3:39 PM

  • oh lmao, i was confused because of the title initially. thanks! great read

    by OlympusHero, Jul 20, 2024, 5:00 AM

  • It should be under August 2023

    by greenturtle3141, Jul 11, 2024, 11:44 PM

  • does this blog still have the post about your math journey? for some reason i can't find it

    by OlympusHero, Jul 10, 2024, 5:41 PM

  • imagine not tortoise math

    no but seriously really interesting blog

    by fruitmonster97, Apr 2, 2024, 12:39 AM

  • W blog man

    by s12d34, Jan 24, 2024, 11:37 PM

  • very nice blog greenturtle it is very descriptive and fascinating to pay attention to :-D

    by StarLex1, Jan 3, 2024, 3:12 PM

  • orz blog

    by ryanbear, Dec 6, 2023, 9:23 PM

67 shouts
Tags
About Owner
  • Posts: 3555
  • Joined: Oct 14, 2014
Blog Stats
  • Blog created: Oct 23, 2021
  • Total entries: 54
  • Total visits: 41107
  • Total comments: 126
Search Blog
a