2022 AMC and AIME proposals

by djmathman, Feb 18, 2022, 1:11 AM

Had quite a few this year. Probably will be the last year I have this many.
10A 2 / 12A 2 (Summer 2020). Menkara has a $4 \times 6$ index card. If she shortens the length of one side of this card by $1$ inch, the card would have area $18$ square inches. What would the area of the card be in square inches if instead she shortens the length of the other side by $1$ inch?

12A 21 (April/May 2020). Let $ABCD$ be an isosceles trapezoid with $\overline{BC}\parallel \overline{AD}$ and $AB=CD$. Points $X$ and $Y$ lie on diagonal $\overline{AC}$ with $X$ between $A$ and $Y$, as shown in the figure. Suppose $\angle AXD = \angle BYC = 90^\circ$, $AX = 3$, $XY = 1$, and $YC = 2$. What is the area of $ABCD?$
[asy] size(5cm); usepackage("mathptmx"); import geometry; void perp(picture pic=currentpicture, pair O, pair M, pair B, real size=5, pen p=currentpen, filltype filltype = NoFill){ perpendicularmark(pic, M,unit(unit(O-M)+unit(B-M)),size,p,filltype); } pen p=black+linewidth(0.8),q=black+linewidth(4.5); pair C=(0,0),Y=(2,0),X=(3,0),A=(6,0),B=(2,sqrt(5.6)),D=(3,-sqrt(12.6)); draw(A--B--C--D--cycle,p); draw(A--C,p); draw(B--Y,p); draw(D--X,p); dot(A,q); dot(B,q); dot(C,q); dot(D,q); dot(X,q); dot(Y,q); label("2",C--Y,S); label("1",Y--X,S); label("3",X--A,S); label("$A$",A,E); label("$B$",B,N); label("$C$",C,W); label("$D$",D,S); label("$Y$",Y,sqrt(2)*NE); label("$X$",X,N); perp(B,Y,C,8,p); perp(A,X,D,8,p); [/asy]
10B 4 (Summer 2020). At noon on a certain day, Minneapolis is $N$ degrees warmer than St. Louis. At $4{:}00$ the temperature in Minneapolis has fallen by $5$ degrees while the temperature in St. Louis has risen by $3$ degrees, at which time the temperatures in the two cities differ by $2$ degrees. What is the product of all possible values of $N?$

10B 15 (Summer 2019). In square $ABCD$, points $P$ and $Q$ lie on $\overline{AD}$ and $\overline{AB}$, respectively. Segments $\overline{BP}$ and $\overline{CQ}$ intersect at right angles at $R$, with $BR = 6$ and $PR = 7$. What is the area of the square?
[asy] size(130); defaultpen(linewidth(0.6)+fontsize(10)); real r = 3.5; pair A = origin, B = (5,0), C = (5,5), D = (0,5), P = (0,r), Q = (5-r,0), R = intersectionpoint(B--P,C--Q); draw(A--B--C--D--A^^B--P^^C--Q^^rightanglemark(P,R,C,7)); dot("$A$",A,S); dot("$B$",B,S); dot("$C$",C,N); dot("$D$",D,N); dot("$Q$",Q,S); dot("$P$",P,W); dot("$R$",R,1.3*S); label("$7$",(P+R)/2,NE); label("$6$",(R+B)/2,NE); [/asy]
12B 16 (March 2020). Let $a, b,$ and $c$ be positive integers such that $a+b+c=23$ and \[\gcd(a,b)+\gcd(b,c)+\gcd(c,a)=9.\]What is the sum of all possible distinct values of $a^{2}+b^{2}+c^{2}$?

10B 25 (March 2020). A rectangle with side lengths $1{ }$ and $3,$ a square with side length $1,$ and a rectangle $R$ are inscribed inside a larger square as shown. The sum of all possible values for the area of $R$ can be written in the form $\tfrac mn$, where $m$ and $n$ are relatively prime positive integers. What is $m+n?$

[asy] size(6cm); draw((0,0)--(10,0)); draw((0,0)--(0,10)); draw((10,0)--(10,10)); draw((0,10)--(10,10)); draw((1,6)--(0,9)); draw((0,9)--(3,10)); draw((3,10)--(4,7)); draw((4,7)--(1,6)); draw((0,3)--(1,6)); draw((1,6)--(10,3)); draw((10,3)--(9,0)); draw((9,0)--(0,3)); draw((6,13/3)--(10,22/3)); draw((10,22/3)--(8,10)); draw((8,10)--(4,7)); draw((4,7)--(6,13/3)); label("$3$",(9/2,3/2),N); label("$3$",(11/2,9/2),S); label("$1$",(1/2,9/2),E); label("$1$",(19/2,3/2),W); label("$1$",(1/2,15/2),E); label("$1$",(3/2,19/2),S); label("$1$",(5/2,13/2),N); label("$1$",(7/2,17/2),W); label("$R$",(7,43/6),W); [/asy]
AIME I 1 (December 2020). Quadratic polynomials $P(x)$ and $Q(x)$ have leading coefficients of $2$ and $-2$, respectively. The graphs of both polynomials pass through the two points $(16,54)$ and $(20,53)$. Find ${P(0) + Q(0)}$.

AIME I 11 (May/June 2020). Let $ABCD$ be a parallelogram with $\angle BAD < 90^{\circ}$. A circle tangent to sides $\overline{DA}$, $\overline{AB}$, and $\overline{BC}$ intersects diagonal $\overline{AC}$ at points $P$ and $Q$ with $AP < AQ$, as shown. Suppose that $AP = 3$, $PQ = 9$, and $QC = 16$. Then the area of $ABCD$ can be expressed in the form $m\sqrt n$, where $m$ and $n$ are positive integers, and $n$ is not divisible by the square of any prime. Find $m+n$.

[asy]
defaultpen(linewidth(0.6)+fontsize(11));
size(8cm);
pair A,B,C,D,P,Q;
A=(0,0);
label("$A$", A, SW);
B=(6,15);
label("$B$", B, NW);
C=(30,15);
label("$C$", C, NE);
D=(24,0);
label("$D$", D, SE);
P=(5.2,2.6);
label("$P$", (5.8,2.6), N);
Q=(18.3,9.1);
label("$Q$", (18.1,9.7), W);
draw(A--B--C--D--cycle);
draw(C--A);
draw(Circle((10.95,7.45), 7.45));
dot(A^^B^^C^^D^^P^^Q);
[/asy]
AIME II 5 (December 2019). Twenty distinct points are marked on a circle and labeled $1$ through $20$ in clockwise order. A line segment is drawn between every pair of points whose labels differ by a prime number. Find the number of triangles formed whose vertices are among the original $20$ points.

AIME II 8 (April 2020). Find the number of positive integers $n \le 600$ whose value can be uniquely determined when the values of $\left\lfloor \tfrac n4\right\rfloor$, $\left\lfloor\tfrac n5\right\rfloor$, and $\left\lfloor\tfrac n6\right\rfloor$ are given, where $\lfloor x \rfloor$ denotes the greatest integer less than or equal to the real number $x$.

AIME II 11 (February 2020). Let $ABCD$ be a convex quadrilateral with $AB=2, AD=7,$ and $CD=3$ such that the bisectors of acute angles $\angle{DAB}$ and $\angle{ADC}$ intersect at the midpoint of $\overline{BC}.$ Find the square of the area of $ABCD.$

AIME II 15 (December 2019). Two externally tangent circles $\omega_1$ and $\omega_2$ have centers $O_1$ and $O_2$, respectively. A third circle $\Omega$ passing through $O_1$ and $O_2$ intersects $\omega_1$ at $B$ and $C$ and $\omega_2$ at $A$ and $D$, as shown. Suppose that $AB = 2$, $O_1O_2 = 15$, $CD = 16$, and $ABO_1CDO_2$ is a convex hexagon. Find the area of this hexagon.
[asy] import geometry; size(8cm); defaultpen(fontsize(11)); point O1=(0,0),O2=(15,0),B=9*dir(30); circle w1=circle(O1,9),w2=circle(O2,6),o=circle(O1,O2,B); point A=intersectionpoints(o,w2)[1],D=intersectionpoints(o,w2)[0],C=intersectionpoints(o,w1)[0]; filldraw(A--B--O1--C--D--O2--cycle,0.2*red+white,black); draw(w1); draw(w2); draw(O1--O2,dashed); draw(o); dot(O1); dot(O2); dot(A); dot(D); dot(C); dot(B); label("$\omega_1$",8*dir(110),SW); label("$\omega_2$",5*dir(70)+(15,0),SE); label("$O_1$",O1,W); label("$O_2$",O2,E); label("$B$",B,N+1/2*E); label("$A$",A,N+1/2*W); label("$C$",C,S+1/4*W); label("$D$",D,S+1/4*E); label("$15$",midpoint(O1--O2),N); label("$16$",midpoint(C--D),N); label("$2$",midpoint(A--B),S); label("$\Omega$",o.C+(o.r-1)*dir(270)); [/asy]
Overall, I'm quite happy with this group of problems :) I personally believe my AIME proposals are stronger than my AMC proposals, but I'm pleasantly surprised at the reception to my AMC problems, too. (I thought 12B 16 was meh and feared people would hate me for 10B 25....) Personal favorites are probably 10B 15 and AIME II 15, but you could probably convince me that quite a few others are up there, too.
This post has been edited 1 time. Last edited by djmathman, Feb 18, 2022, 1:13 AM

Comment

5 Comments

The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
First comment somehow? Anyway, great job on getting 2 first 5 problems :D

by peace09, Feb 18, 2022, 3:53 PM

The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
Nice! How do you come up with those :)

by mag1c, Feb 19, 2022, 3:16 AM

The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
I really liked AMC 10B P25 until I saw you say that you didn't like it

by ihatemath123, May 8, 2022, 10:42 PM

The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
I'm gonna miss a dj-dominated amc/aime :no:

by samrocksnature, Oct 17, 2022, 6:14 AM

The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
Absolutely loved 10B 15, pleasantly stunned by how easy it could be.

by Idunknowhowaboutyou, Nov 12, 2022, 7:38 PM

A blog documenting a (no longer) high school youth and his struggles with advancing his mathematical skill.

avatar

djmathman
Archives
- April 2025
+ November 2024
+ November 2023
+ February 2023
+ November 2022
+ November 2020
+ July 2020
+ December 2019
+ October 2019
+ July 2019
+ April 2019
+ February 2019
+ October 2018
+ November 2017
+ October 2017
+ September 2017
+ June 2017
+ February 2015
+ January 2012
Shouts
Submit
  • dj so orz :omighty:

    by Yiyj1, Mar 29, 2025, 1:42 AM

  • legendary problem writer

    by Clew28, Jul 29, 2024, 7:20 PM

  • orz $$\,$$

    by balllightning37, Jul 26, 2024, 1:05 AM

  • hi dj $ $ $ $

    by OronSH, Jul 23, 2024, 2:14 AM

  • i wanna submit my own problems lol

    by ethanzhang1001, Jul 20, 2024, 9:54 PM

  • hi dj, may i have the role of contributer? :D

    by lpieleanu, Feb 23, 2024, 1:31 AM

  • This was helpful!

    by YIYI-JP, Nov 23, 2023, 12:42 PM

  • waiting for a recap of your amc proposals for this year :D

    by ihatemath123, Feb 17, 2023, 3:18 PM

  • also happy late bday man! i missed it by 2 days but hope you are enjoyed it

    by ab456, Dec 30, 2022, 10:58 AM

  • Contrib? :D

    by MC413551, Nov 20, 2022, 10:48 PM

  • :love: tfw kakuro appears on amc :love:

    by bissue, Aug 18, 2022, 4:32 PM

  • Hi dj :)

    by 799786, Aug 10, 2022, 1:44 AM

  • Roses are red,
    Wolfram is banned,
    The best problem writer is
    Djmathman

    by ihatemath123, Aug 6, 2022, 12:19 AM

  • hello :)

    by aidan0626, Jul 26, 2022, 5:49 PM

  • Do you have a link to your main blog that you started after graduating from high school, I couldn't find it. @dj I met you IRL at Awesome Math summer Program several years ago.

    by First, Mar 1, 2022, 5:18 PM

363 shouts
Tags
About Owner
  • Posts: 7938
  • Joined: Feb 23, 2011
Blog Stats
  • Blog created: Aug 5, 2011
  • Total entries: 567
  • Total visits: 486053
  • Total comments: 1520
Search Blog
a