Difference between revisions of "2019 AIME II Problems"
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==Problem 5== | ==Problem 5== | ||
− | Four ambassadors and one advisor for each of | + | Four ambassadors and one advisor for each of them are to be seated at a round table with <math>12</math> chairs numbered in order <math>1</math> to <math>12</math>. Each ambassador must sit in an even-numbered chair. Each advisor must sit in a chair adjacent to his or her ambassador. There are <math>N</math> ways for the <math>8</math> people to be seated at the table under these conditions. Find the remainder when <math>N</math> is divided by <math>1000</math>. |
[[2019 AIME II Problems/Problem 5 | Solution]] | [[2019 AIME II Problems/Problem 5 | Solution]] | ||
==Problem 6== | ==Problem 6== | ||
− | In a Martian civilization, all logarithms whose bases are not specified | + | In a Martian civilization, all logarithms whose bases are not specified are assumed to be base <math>b</math>, for some fixed <math>b\ge2</math>. A Martian student writes down |
<cmath>3\log(\sqrt{x}\log x)=56</cmath> | <cmath>3\log(\sqrt{x}\log x)=56</cmath> | ||
<cmath>\log_{\log x}(x)=54</cmath> | <cmath>\log_{\log x}(x)=54</cmath> | ||
Line 46: | Line 46: | ||
==Problem 8== | ==Problem 8== | ||
− | The polynomial <math>f(z)=az^{2018}+bz^{2017}+cz^{2016}</math> has real coefficients not exceeding <math>2019</math> and <math>f\left(\tfrac{1+\sqrt3i}{2}\right)=2015+2019\sqrt3i</math>. Find the remainder when <math>f(1)</math> is divided by <math>1000</math>. | + | The polynomial <math>f(z)=az^{2018}+bz^{2017}+cz^{2016}</math> has real coefficients not exceeding <math>2019,</math> and <math>f\left(\tfrac{1+\sqrt3i}{2}\right)=2015+2019\sqrt3i</math>. Find the remainder when <math>f(1)</math> is divided by <math>1000</math>. |
[[2019 AIME II Problems/Problem 8 | Solution]] | [[2019 AIME II Problems/Problem 8 | Solution]] | ||
==Problem 9== | ==Problem 9== | ||
+ | Call a positive integer <math>n</math> <math>k</math>-<i>pretty</i> if <math>n</math> has exactly <math>k</math> positive divisors and <math>n</math> is divisible by <math>k</math>. For example, <math>18</math> is <math>6</math>-pretty. Let <math>S</math> be the sum of the positive integers less than <math>2019</math> that are <math>20</math>-pretty. Find <math>\tfrac{S}{20}</math>. | ||
[[2019 AIME II Problems/Problem 9 | Solution]] | [[2019 AIME II Problems/Problem 9 | Solution]] | ||
==Problem 10== | ==Problem 10== | ||
+ | There is a unique angle <math>\theta</math> between <math>0^\circ</math> and <math>90^\circ</math> such that for nonnegative integers <math>n,</math> the value of <math>\tan(2^n\theta)</math> is positive when <math>n</math> is a multiple of <math>3</math>, and negative otherwise. The degree measure of <math>\theta</math> is <math>\tfrac{p}{q}</math>, where <math>p</math> and <math>q</math> are relatively prime positive integers. Find <math>p+q</math>. | ||
[[2019 AIME II Problems/Problem 10 | Solution]] | [[2019 AIME II Problems/Problem 10 | Solution]] | ||
==Problem 11== | ==Problem 11== | ||
+ | Triangle <math>ABC</math> has side lengths <math>AB=7,BC=8,</math> and <math>CA=9.</math> Circle <math>\omega_1</math> passes through <math>B</math> and is tangent to line <math>AC</math> at <math>A.</math> Circle <math>\omega_2</math> passes through <math>C</math> and is tangent to line <math>AB</math> at <math>A.</math> Let <math>K</math> be the intersection of circles <math>\omega_1</math> and <math>\omega_2</math> not equal to <math>A.</math> Then <math>AK=\tfrac{m}{n},</math> where <math>m</math> and <math>n</math> are relatively prime positive integers. Find <math>m+n.</math> | ||
[[2019 AIME II Problems/Problem 11 | Solution]] | [[2019 AIME II Problems/Problem 11 | Solution]] | ||
==Problem 12== | ==Problem 12== | ||
+ | For <math>n\ge1</math> call a finite sequence <math>(a_1,a_2,\ldots,a_n)</math> of positive integers <i>progressive</i> if <math>a_i<a_{i+1}</math> and <math>a_i</math> divides <math>a_{i+1}</math> for <math>1\le i\le n-1</math>. Find the number of progressive sequences such that the sum of the terms in the sequence is equal to <math>360.</math> | ||
[[2019 AIME II Problems/Problem 12 | Solution]] | [[2019 AIME II Problems/Problem 12 | Solution]] | ||
==Problem 13== | ==Problem 13== | ||
+ | Regular octagon <math>A_1A_2A_3A_4A_5A_6A_7A_8</math> is inscribed in a circle of area <math>1.</math> Point <math>P</math> lies inside the circle so that the region bounded by <math>\overline{PA_1},\overline{PA_2},</math> and the minor arc <math>\widehat{A_1A_2}</math> of the circle has area <math>\tfrac{1}{7},</math> while the region bounded by <math>\overline{PA_3},\overline{PA_4},</math> and the minor arc <math>\widehat{A_3A_4}</math> of the circle has area <math>\tfrac{1}{9}.</math> There is a positive integer <math>n</math> such that the area of the region bounded by <math>\overline{PA_6},\overline{PA_7},</math> and the minor arc <math>\widehat{A_6A_7}</math> of the circle is equal to <math>\tfrac{1}{8}-\tfrac{\sqrt2}{n}.</math> Find <math>n.</math> | ||
[[2019 AIME II Problems/Problem 13 | Solution]] | [[2019 AIME II Problems/Problem 13 | Solution]] | ||
==Problem 14== | ==Problem 14== | ||
+ | Find the sum of all positive integers <math>n</math> such that, given an unlimited supply of stamps of denominations <math>5,n,</math> and <math>n+1</math> cents, <math>91</math> cents is the greatest postage that cannot be formed. | ||
[[2019 AIME II Problems/Problem 14 | Solution]] | [[2019 AIME II Problems/Problem 14 | Solution]] | ||
==Problem 15== | ==Problem 15== | ||
+ | In acute triangle <math>ABC,</math> points <math>P</math> and <math>Q</math> are the feet of the perpendiculars from <math>C</math> to <math>\overline{AB}</math> and from <math>B</math> to <math>\overline{AC}</math>, respectively. Line <math>PQ</math> intersects the circumcircle of <math>\triangle ABC</math> in two distinct points, <math>X</math> and <math>Y</math>. Suppose <math>XP=10</math>, <math>PQ=25</math>, and <math>QY=15</math>. The value of <math>AB\cdot AC</math> can be written in the form <math>m\sqrt n</math> where <math>m</math> and <math>n</math> are positive integers, and <math>n</math> is not divisible by the square of any prime. Find <math>m+n</math>. | ||
[[2019 AIME II Problems/Problem 15 | Solution]] | [[2019 AIME II Problems/Problem 15 | Solution]] | ||
− | {{AIME box|year=2019|n=II|before=[[2019 AIME I]]|after=[[2020 AIME I]]}} | + | {{AIME box|year=2019|n=II|before=[[2019 AIME I Problems]]|after=[[2020 AIME I Problems]]}} |
{{MAA Notice}} | {{MAA Notice}} |
Latest revision as of 13:45, 21 August 2023
2019 AIME II (Answer Key) | AoPS Contest Collections • PDF | ||
Instructions
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1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 |
Contents
Problem 1
Two different points, and , lie on the same side of line so that and are congruent with , and . The intersection of these two triangular regions has area , where and are relatively prime positive integers. Find .
Problem 2
Lily pads lie in a row on a pond. A frog makes a sequence of jumps starting on pad . From any pad the frog jumps to either pad or pad chosen randomly with probability and independently of other jumps. The probability that the frog visits pad is , where and are relatively prime positive integers. Find .
Problem 3
Find the number of -tuples of positive integers that satisfy the following system of equations:
Problem 4
A standard six-sided fair die is rolled four times. The probability that the product of all four numbers rolled is a perfect square is , where and are relatively prime positive integers. Find .
Problem 5
Four ambassadors and one advisor for each of them are to be seated at a round table with chairs numbered in order to . Each ambassador must sit in an even-numbered chair. Each advisor must sit in a chair adjacent to his or her ambassador. There are ways for the people to be seated at the table under these conditions. Find the remainder when is divided by .
Problem 6
In a Martian civilization, all logarithms whose bases are not specified are assumed to be base , for some fixed . A Martian student writes down and finds that this system of equations has a single real number solution . Find .
Problem 7
Triangle has side lengths , and . Lines , and are drawn parallel to , and , respectively, such that the intersections of , and with the interior of are segments of lengths , and , respectively. Find the perimeter of the triangle whose sides lie on lines , and .
Problem 8
The polynomial has real coefficients not exceeding and . Find the remainder when is divided by .
Problem 9
Call a positive integer -pretty if has exactly positive divisors and is divisible by . For example, is -pretty. Let be the sum of the positive integers less than that are -pretty. Find .
Problem 10
There is a unique angle between and such that for nonnegative integers the value of is positive when is a multiple of , and negative otherwise. The degree measure of is , where and are relatively prime positive integers. Find .
Problem 11
Triangle has side lengths and Circle passes through and is tangent to line at Circle passes through and is tangent to line at Let be the intersection of circles and not equal to Then where and are relatively prime positive integers. Find
Problem 12
For call a finite sequence of positive integers progressive if and divides for . Find the number of progressive sequences such that the sum of the terms in the sequence is equal to
Problem 13
Regular octagon is inscribed in a circle of area Point lies inside the circle so that the region bounded by and the minor arc of the circle has area while the region bounded by and the minor arc of the circle has area There is a positive integer such that the area of the region bounded by and the minor arc of the circle is equal to Find
Problem 14
Find the sum of all positive integers such that, given an unlimited supply of stamps of denominations and cents, cents is the greatest postage that cannot be formed.
Problem 15
In acute triangle points and are the feet of the perpendiculars from to and from to , respectively. Line intersects the circumcircle of in two distinct points, and . Suppose , , and . The value of can be written in the form where and are positive integers, and is not divisible by the square of any prime. Find .
2019 AIME II (Problems • Answer Key • Resources) | ||
Preceded by 2019 AIME I Problems |
Followed by 2020 AIME I Problems | |
1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 | ||
All AIME Problems and Solutions |
The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions.