arthham

Exam

AIME

Conducting Body
Mathematical Association of America (MAA)
Eligibility
By invitation based on AMC 10/12 scores
Syllabus
Advanced algebra, geometry, trigonometry, number theory, combinatorics
Question Type
15 integer-answer questions (0-999)
Duration
3 hours
Marking
1 point per correct answer, no negative marking
Frequency
Annually, with two testing dates
Qualifies For
USA Mathematical Olympiad (USAMO/USAJMO)

The American Invitational Mathematics Examination (AIME) is the second stage in the series of contests used to select the United States team for the International Mathematical Olympiad. It is an invitational exam for high school students who achieve a top score on the AMC 10 or AMC 12 competitions. A student's AIME score is combined with their AMC score to determine qualification for the USA Mathematical Olympiad (USAMO) and USA Junior Mathematical Olympiad (USAJMO).

The paper consists of 15 questions to be answered in three hours. Unlike the AMC, the AIME is not a multiple-choice test. Every answer is an integer from 0 to 999, and students must derive this number themselves and write it on the answer sheet. There is no partial credit awarded for showing work.

The AIME is substantially more difficult than the AMC. The problems require a deeper understanding of topics like number theory, geometry, and combinatorics, and often need creative, multi-step solutions. The integer-answer format makes the exam particularly challenging, as a small arithmetic error leads to a completely wrong answer. Managing time is also difficult, with an average of only twelve minutes available for each complex problem.

How a question gets worked here

From a mathematics paper rather than AIME, worked the way every question on this site is. AIME questions are being added.

JEE Advanced 2009

Let (x, y, z) be points with integer coordinates satisfying the system of homogeneous equations 3x−y−z=0,−3x+z=0,−3x+2y+z=0.3x - y - z = 0, -3x + z = 0, -3x + 2y + z = 0. Then the number of such points for which x2+y2+z2≤100x^{2} + y^{2} + z^{2} \le 100 is ______.
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3x−y−z=0,−3x+z=0,−3x+2y+z=03x - y - z = 0,\quad -3x + z = 0,\quad -3x + 2y + z = 0

x,y,z∈Zx, y, z \in \mathbb{Z}

To find: number of points with x2+y2+z2≤100\text{To find: number of points with } x^2 + y^2 + z^2 \le 100

Step 1: solve the system⇒all integer solutions (x,y,z)\text{Step 1: solve the system} \Rightarrow \text{all integer solutions } (x, y, z)

Step 2: keep those with x2+y2+z2≤100\text{Step 2: keep those with } x^2 + y^2 + z^2 \le 100

−3x+z=0⇒z=3x-3x + z = 0 \Rightarrow z = 3x

3x−y−z=0⇒3x−y−3x=03x - y - z = 0 \Rightarrow 3x - y - 3x = 0

⇒y=0\Rightarrow y = 0

−3x+2y+z=−3x+0+3x=0 ✓-3x + 2y + z = -3x + 0 + 3x = 0\ \checkmark

(x,y,z)=(t,0,3t),t∈Z(x, y, z) = (t, 0, 3t),\quad t \in \mathbb{Z}

line through the origin, direction (1,0,3)\text{line through the origin, direction } (1, 0, 3)

x2+y2+z2≤100x^2 + y^2 + z^2 \le 100

t2+0+(3t)2=10t2≤100t^2 + 0 + (3t)^2 = 10t^2 \le 100

t2≤10⇒∣t∣≤3t^2 \le 10 \Rightarrow |t| \le 3

t∈{−3,−2,−1,0,1,2,3}t \in \{-3, -2, -1, 0, 1, 2, 3\}

Number of values of t=7\text{Number of values of } t = 7

(t,0,3t): t=−3,…,3⇒7 points(t, 0, 3t):\ t = -3,\dots,3 \Rightarrow 7 \text{ points}

7\boxed{7}

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