MathDB

25

Part of 2022 AMC 10

Problems(2)

sussy baka stop intersecting in my lattice points

Source: 2022 AMC 10A #25

11/11/2022
Let RR, SS, and TT be squares that have vertices at lattice points (i.e., points whose coordinates are both integers) in the coordinate plane, together with their interiors. The bottom edge of each square is on the x-axis. The left edge of RR and the right edge of SS are on the yy-axis, and RR contains 94\frac{9}{4} as many lattice points as does SS. The top two vertices of TT are in RSR \cup S, and TT contains 14\frac{1}{4} of the lattice points contained in RSR \cup S. See the figure (not drawn to scale).
[asy] //kaaaaaaaaaante314 size(8cm); import olympiad; label(scale(.8)*"yy", (0,60), N); label(scale(.8)*"xx", (60,0), E); filldraw((0,0)--(55,0)--(55,55)--(0,55)--cycle, yellow+orange+white+white); label(scale(1.3)*"RR", (55/2,55/2)); filldraw((0,0)--(0,28)--(-28,28)--(-28,0)--cycle, green+white+white); label(scale(1.3)*"SS",(-14,14)); filldraw((-10,0)--(15,0)--(15,25)--(-10,25)--cycle, red+white+white); label(scale(1.3)*"TT",(3.5,25/2)); draw((0,-10)--(0,60),EndArrow(TeXHead)); draw((-34,0)--(60,0),EndArrow(TeXHead));[/asy]
The fraction of lattice points in SS that are in STS \cap T is 27 times the fraction of lattice points in RR that are in RTR \cap T. What is the minimum possible value of the edge length of RR plus the edge length of SS plus the edge length of TT?
<spanclass=latexbold>(A)</span>336<spanclass=latexbold>(B)</span>337<spanclass=latexbold>(C)</span>338<spanclass=latexbold>(D)</span>339<spanclass=latexbold>(E)</span>340<span class='latex-bold'>(A) </span>336\qquad<span class='latex-bold'>(B) </span>337\qquad<span class='latex-bold'>(C) </span>338\qquad<span class='latex-bold'>(D) </span>339\qquad<span class='latex-bold'>(E) </span>340
AMCAMC 102022 AMC 10a2022 AMClattice pointscoordinate geometrysquare
among us sequence

Source: 2022 AMC 10B #25 / 2022 AMC 12B #23

11/17/2022
Let x0x_{0}, x1x_{1}, x2x_{2}, \cdots be a sequence of numbers, where each xkx_{k} is either 00 or 11. For each positive integer nn, define Sn=k=0n1xk2kS_{n} = \displaystyle\sum^{n-1}_{k=0}{x_{k}2^{k}}
Suppose 7Sn1(mod2n)7S_{n} \equiv 1\pmod {2^{n}} for all n1n\geq 1. What is the value of the sum x2019+2x2020+4x2021+8x2022?x_{2019}+2x_{2020}+4x_{2021}+8x_{2022}?
<spanclass=latexbold>(A)</span> 6<spanclass=latexbold>(B)</span> 7<spanclass=latexbold>(C)</span> 12<spanclass=latexbold>(D)</span> 14<spanclass=latexbold>(E)</span> 15 <span class='latex-bold'>(A)</span>\ 6 \qquad <span class='latex-bold'>(B)</span>\ 7 \qquad <span class='latex-bold'>(C)</span>\ 12 \qquad <span class='latex-bold'>(D)</span>\ 14 \qquad <span class='latex-bold'>(E)</span>\ 15
AMCAMC 10AMC 122022 AMC2022 AMC 10B2022 AMC 12BSequence