Difference between revisions of "Mock AIME 4 2005-2006/Problems"
Line 1: | Line 1: | ||
− | <math>\ | + | == Problem 1 == |
+ | Suppose <math>n</math> is a positive integer. Let <math>f(n)</math> be the sum of the distinct positive prime divisors of <math>n</math> less than <math>50</math> (e.g. <math>f(12) = 2+3 = 5</math> and <math>f(101) = 0</math>). Evaluate the remainder when <math>f(1)+f(2)+\cdots+f(99)</math> is divided by <math>1000</math>. | ||
+ | |||
+ | [[Mock AIME 5 2005-2006/Problem 1|Solution]] | ||
+ | |||
+ | == Problem 2 == | ||
+ | A circle <math>\omega_1</math> of radius <math>6\sqrt{2}</math> is internally tangent to a larger circle <math>\omega_2</math> of radius <math>12\sqrt{2}</math> such that the center of <math>\omega_2</math> lies on <math>\omega_1</math>. A diameter <math>AB</math> of <math>\omega_2</math> is drawn tangent to <math>\omega_1</math>. A second line <math>l</math> is drawn from <math>B</math> tangent to <math>\omega_1</math>. Let the line tangent to <math>\omega_2</math> at <math>A</math> intersect <math>l</math> at <math>C</math>. Find the area of <math>\triangle ABC</math>. | ||
+ | |||
+ | [[Mock AIME 5 2005-2006/Problem 2|Solution]] | ||
+ | |||
+ | == Problem 3 == | ||
+ | A <math>\emph hailstone</math> number <math>n = d_1d_2 \cdots d_k</math>, where <math>d_i</math> denotes the <math>i</math>th digit in the base-<math>10</math> representation of <math>n</math> for <math>i = 1,2, \ldots,k</math>, is a positive integer with distinct nonzero digits such that <math>d_m < d_{m-1}</math> if <math>m</math> is even and <math>d_m > d_{m-1}</math> if <math>m</math> is odd for <math>m = 1,2,\ldots,k</math> (and <math>d_0 = 0</math>). Let <math>a</math> be the number of four-digit hailstone numbers and <math>b</math> be the number of three-digit hailstone numbers. Find <math>a+b</math>. | ||
+ | |||
+ | [[Mock AIME 5 2005-2006/Problem 3|Solution]] | ||
+ | |||
+ | == Problem 4 == | ||
+ | Let <math>m</math> and <math>n</math> be integers such that <math>1 < m \le 10</math> and <math>m < n \le 100</math>. Given that <math>x = \log_m{n}</math> and <math>y = \log_n{m}</math>, find the number of ordered pairs <math>(m,n)</math> such that <math> \displaystyle \lfloor x \rfloor = \lceil y \rceil</math>. (<math>\lfloor a \rfloor</math> is the greatest integer less than or equal to <math>a</math> and <math>\lceil a \rceil</math> is the least integer greater than or equal to <math>a</math>). | ||
+ | |||
+ | [[Mock AIME 5 2005-2006/Problem 4|Solution]] | ||
+ | |||
+ | == Problem 5 == | ||
+ | Find the largest prime divisor of <math>25^2+72^2</math>. | ||
+ | |||
+ | [[Mock AIME 5 2005-2006/Problem 5|Solution]] | ||
+ | |||
+ | == Problem 6 == | ||
+ | <math>P_1</math>, <math>P_2</math>, and <math>P_3</math> are polynomials defined by: | ||
+ | |||
+ | : <math>P_1(x) = 1+x+x^3+x^4+\cdots+x^{96}+x^{97}+x^{99}+x^{100}</math> | ||
+ | : <math>P_2(x) = 1-x+x^2-\cdots-x^{99}+x^{100}</math> | ||
+ | : <math>P_3(x) = 1+x+x^2+\cdots+x^{66}+x^{67}</math> | ||
+ | |||
+ | Find the number of distinct complex roots of <math>P_1 \cdot P_2 \cdot P_3</math>. | ||
+ | |||
+ | [[Mock AIME 5 2005-2006/Problem 6|Solution]] | ||
+ | |||
+ | == Problem 7 == | ||
+ | A coin of radius <math>1</math> is flipped onto an <math>500 \times 500</math> square grid divided into <math>2500</math> equal squares. Circles are inscribed in <math>n</math> of these <math>2500</math> squares. Let <math>P_n</math> be the probability that, given that the coin lands completely within one of the smaller squares, it also lands completely within one of the circles. Let <math>P</math> be the probability that, when flipped onto the grid, the coin lands completely within one of the smaller squares. Let <math>n_0</math> smallest value of <math>n</math> such that <math>P_n > P</math>. Find the value of <math>\displaystyle \left\lfloor \frac{n_0}{3} \right\rfloor</math>. | ||
+ | |||
+ | [[Mock AIME 5 2005-2006/Problem 7|Solution]] | ||
+ | |||
+ | == Problem 8 == | ||
+ | Let <math>P</math> be a polyhedron with <math>37</math> faces, all of which are equilateral triangles, squares, or regular pentagons with equal side length. Given there is at least one of each type of face and there are twice as many pentagons as triangles, what is the sum of all the possible number of vertices <math>P</math> can have? | ||
+ | |||
+ | [[Mock AIME 5 2005-2006/Problem 8|Solution]] | ||
+ | |||
+ | == Problem 9 == | ||
+ | <math>13</math> nondistinguishable residents are moving into <math>7</math> distinct houses in Conformistville, with at least one resident per house. In how many ways can the residents be assigned to these houses such that there is at least one house with <math>4</math> residents? | ||
+ | |||
+ | [[Mock AIME 5 2005-2006/Problem 9|Solution]] | ||
+ | |||
+ | == Problem 10 == | ||
+ | Find the smallest positive integer <math>n</math> such that <math>\displaystyle {2n \choose n}</math> is divisible by all the primes between <math>10</math> and <math>30</math>. | ||
+ | |||
+ | [[Mock AIME 5 2005-2006/Problem 10|Solution]] | ||
+ | |||
+ | == Problem 11 == | ||
+ | Let <math>A</math> be a subset of consecutive elements of <math>S = \{n, n+1, \ldots, n+999\}</math> where <math>n</math> is a positive integer. Define <math>\displaystyle \mu(A) = \sum_{k \in A} \tau(k)</math>, where <math>\tau(k) = 1</math> if <math>k</math> has an odd number of divisors and <math>\tau(k) = 0</math> if <math>k</math> has an even number of divisors. For how many <math>n \le 1000</math> does there exist an <math>A</math> such that <math>|A| = 620</math> and <math>\mu(A) = 11</math>? (<math>|X|</math> denotes the cardinality of the set <math>X</math>, or the number of elements in <math>X</math>) | ||
+ | |||
+ | [[Mock AIME 5 2005-2006/Problem 11|Solution]] | ||
+ | |||
+ | == Problem 12 == | ||
+ | Let <math>ABC</math> be a triangle with <math>AB = 13</math>, <math>BC = 14</math>, and <math>AC = 15</math>. Let <math>D</math> be the foot of the altitude from <math>A</math> to <math>BC</math> and <math>E</math> be the point on <math>BC</math> between <math>D</math> and <math>C</math> such that <math>BD = CE</math>. Extend <math>AE</math> to meet the circumcircle of <math>ABC</math> at <math>F</math>. If the area of triangle <math>FAC</math> is <math>\displaystyle \frac{m}{n}</math>, where <math>m</math> and <math>n</math> are relatively prime positive integers, find <math>m+n</math>. | ||
+ | |||
+ | [[Mock AIME 5 2005-2006/Problem 12|Solution]] | ||
+ | |||
+ | == Problem 13 == | ||
+ | Let <math>S</math> be the set of positive integers with only odd digits satisfying the following condition: any <math>x \in S</math> with <math>n</math> digits must be divisible by <math>5^n</math>. Let <math>A</math> be the sum of the <math>20</math> smallest elements of <math>S</math>. Find the remainder upon dividing <math>A</math> by <math>1000</math>. | ||
+ | |||
+ | [[Mock AIME 5 2005-2006/Problem 13|Solution]] | ||
+ | |||
+ | == Problem 14 == | ||
+ | Let <math>ABC</math> be a triangle such that <math>AB = 68</math>, <math>BC = 100</math>, and <math>\displaystyle CA = 112</math>. Let <math>H</math> be the orthocenter of <math>\triangle ABC</math> (intersection of the altitudes). Let <math>D</math> be the midpoint of <math>BC</math>, <math>E</math> be the midpoint of <math>CA</math>, and <math>F</math> be the midpoint of <math>AB</math>. Points <math>X</math>, <math>Y</math>, and <math>Z</math> are constructed on <math>HD</math>, <math>HE</math>, and <math>HF</math>, respectively, such that <math>D</math> is the midpoint of <math>XH</math>, <math>E</math> is the midpoint of <math>YH</math>, and <math>F</math> is the midpoint of <math>ZH</math>. Find <math>AX+BY+CZ</math>. | ||
+ | |||
+ | [[Mock AIME 5 2005-2006/Problem 14|Solution]] | ||
+ | |||
+ | == Problem 15 == | ||
+ | <math>2006</math> colored beads are placed on a necklace (circular ring) such that each bead is adjacent to two others. The beads are labeled <math>a_0</math>, <math>a_1</math>, <math>\ldots</math>, <math>a_{2005}</math> around the circle in order. Two beads <math>a_i</math> and <math>a_j</math>, where <math>i</math> and <math>j</math> are non-negative integers, satisfy <math>a_i = a_j</math> if and only if the color of <math>a_i</math> is the same as the color of <math>a_j</math>. Given that there exists no non-negative integer <math>m < 2006</math> and positive integer <math>n < 1003</math> such that <math>a_m = a_{m-n} = a_{m+n}</math>, where all subscripts are taken <math>\pmod{2006}</math>, find the minimum number of different colors of beads on the necklace. | ||
+ | |||
+ | [[Mock AIME 5 2005-2006/Problem 15|Solution]] | ||
+ | |||
+ | == See also == | ||
+ | * [[Mock AIME 5 2005-2006]] | ||
+ | * [[Mock AIME]] | ||
+ | * A [http://wangsblog.com/jeffrey/MockAIME5.pdf .pdf] version of the problems | ||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | http://www.mathlinks.ro/Forum/latexrender/pictures/2ea0ce047615395691113a82d6c190b3.gif | ||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
1. A 5-digit number is leet if and only if the sum of the first 2 digits, the sum of the last 2 digits and the middle digit are equal. How many 5-digit leet numbers exist? | 1. A 5-digit number is leet if and only if the sum of the first 2 digits, the sum of the last 2 digits and the middle digit are equal. How many 5-digit leet numbers exist? | ||
− | 2. Qin Shi Huang wants to count the number of warriors he has to invade China. He puts his warriors into lines with the most people such that they have even length. The people left over are the remainder. He makes 2 lines, with a remainder of 1, 3 lines with a remainder of 2, 4 lines with a remainder of 3, 5 lines with a remainder of 4, and 6 lines with a remainder of 5. Find the minimum number of warriors that he has. | + | 2. Qin Shi Huang wants to count the number of warriors he has to invade China. He puts his warriors into lines with the most people such that they have even length. The people left over are the remainder. He makes 2 lines, with a remainder of 1, 3 lines with a remainder of 2, 4 lines with a remainder of 3, 5 lines with a remainder of 4, and 6 lines with a remainder of 5. Find the minimum number of warriors that he has. |
− | 3. T_1 is a regular tetrahedron. Tetrahedron T_2 is formed by connecting the centers of the faces of T_1. Generally, a new tetrahedron T_{n+1} is formed by connecting the centers of the faces of T_n. V_n is the volume of tetrahedron T_n. \frac{V_{2006}}{V_1}=\frac{m}{n} where m and n are coprime positive integers, find the remainder when m+n is divided by 1000. | + | 3. <math>T_1</math> is a regular tetrahedron. Tetrahedron <math>T_2</math> is formed by connecting the centers of the faces of <math>T_1</math>. Generally, a new tetrahedron <math>T_{n+1}</math> is formed by connecting the centers of the faces of <math>T_n</math>. <math>V_n</math> is the volume of tetrahedron <math>T_n</math>. <math>\frac{V_{2006}}{V_1}=\frac{m}{n}</math> where <math>m</math> and <math>n</math> are coprime positive integers, find the remainder when <math>m+n</math> is divided by <math>1000</math>. |
− | 4. Let P(x)=\sum_{i=1}^{20}(-x)^{20-i}(x+i)^i. Let K be the product of the roots. How many digits are does \lfloor K \rfloor have where \lfloor x \rfloor denotes the greatest integer less than or equal to x? | + | 4. Let <math>P(x)=\sum_{i=1}^{20}(-x)^{20-i}(x+i)^i</math>. Let <math>K</math> be the product of the roots. How many digits are does <math>\lfloor K \rfloor</math> have where <math>\lfloor x \rfloor</math> denotes the greatest integer less than or equal to <math>x</math>? |
− | 5. A parabola P: y=x^2 is rotated 135 degrees clockwise about the origin to P'. This image is translated upward \frac{8+\sqrt{2}}{2} to P''. Point A: (0,0), B: (256,0), and C is in Quadrant I, on P''. If the area of \triangle ABC is at a maximum, it is a\sqrt{b}+c where a, b and c are integers and b is square free, find a+b+c. | + | 5. A parabola <math>P: y=x^2</math> is rotated <math>135</math> degrees clockwise about the origin to <math>P'</math>. This image is translated upward <math>\frac{8+\sqrt{2}}{2}</math> to <math>P''</math>. Point <math>A: (0,0)</math>, <math>B: (256,0)</math>, and <math>C</math> is in Quadrant I, on <math>P''</math>. If the area of <math>\triangle ABC</math> is at a maximum, it is <math>a\sqrt{b}+c</math> where <math>a</math>, <math>b</math> and <math>c</math> are integers and <math>b</math> is square free, find <math>a+b+c</math>. |
− | 6. Define a sequence a_0=2006 and a_{n+1}=(n+1)^{a_n} for all positive integers n. Find the remainder when a_{2007} is divided by 1000. | + | 6. Define a sequence <math>a_0=2006</math> and <math>a_{n+1}=(n+1)^{a_n}</math> for all positive integers <math>n</math>. Find the remainder when <math>a_{2007}</math> is divided by <math>1000</math>. |
− | 7. f(x) is a function that satisfies 3f(x)=2x+1-f(\frac{1}{1-x}) for all defined x. Suppose that the sum of the zeros of f(x)=\frac{m}{n} where m and n are coprime positive integers, find m^2+n^2. | + | 7. <math>f(x)</math> is a function that satisfies <math>3f(x)=2x+1-f(\frac{1}{1-x})</math> for all defined <math>x</math>. Suppose that the sum of the zeros of <math>f(x)=\frac{m}{n}</math> where <math>m</math> and <math>n</math> are coprime positive integers, find <math>m^2+n^2</math>. |
− | 8. R is a solution to x+\frac{1}{x}=\frac{ \sin210^{\circ} }{\sin285^{\circ} }. Suppose that \frac{1}{R^{2006}}+R^{2006}=A find \lfloor A^{10} \rfloor where \lfloor x \rfloor is the greatest integer less than or equal to x. | + | 8. <math>R</math> is a solution to <math>x+\frac{1}{x}=\frac{ \sin210^{\circ} }{\sin285^{\circ} }</math>. Suppose that <math>\frac{1}{R^{2006}}+R^{2006}=A</math> find <math>\lfloor A^{10} \rfloor</math> where <math>\lfloor x \rfloor</math> is the greatest integer less than or equal to <math>x</math>. |
− | 9. Zeus, Athena, and Posideon arrive at Mount Olympus at a random time between 12:00 pm and 12:00 am, and stay for 3 hours. All three hours does not need to fall within 12 pm to 12 am. If any of the 2 gods see each other during 12 pm to 12 am, it will be a good day. The probability of it being a good day is \frac{m}{n} where m and n are coprime positive integers, find m+n. | + | 9. Zeus, Athena, and Posideon arrive at Mount Olympus at a random time between 12:00 pm and 12:00 am, and stay for 3 hours. All three hours does not need to fall within 12 pm to 12 am. If any of the 2 gods see each other during 12 pm to 12 am, it will be a good day. The probability of it being a good day is <math>\frac{m}{n}</math> where <math>m</math> and <math>n</math> are coprime positive integers, find <math>m+n</math>. |
− | 10. Define S= \tan^2{1^{\circ}}+\tan^2{3^{\circ}}+\tan^2{5^{\circ}}+...+\tan^2{87^{\circ}}+\tan^2{89^{\circ}}. Find the remainder when S is divided by 1000. | + | 10. Define <math>S= \tan^2{1^{\circ}}+\tan^2{3^{\circ}}+\tan^2{5^{\circ}}+...+\tan^2{87^{\circ}}+\tan^2{89^{\circ}}</math>. Find the remainder when <math>S</math> is divided by <math>1000</math>. |
− | 11. \triangle ABC is isosceles with \angle C= 90^{\circ}. A point P lies inside the triangle such that AP=33, CP=28\sqrt{2}, and BP=65. Let A be the area of \triangle ABC. Find the remainder when 2A is divided by 1000. | + | 11. <math>\triangle ABC</math> is isosceles with <math>\angle C= 90^{\circ}</math>. A point <math>P</math> lies inside the triangle such that <math>AP=33</math>, <math>CP=28\sqrt{2}</math>, and <math>BP=65</math>. Let <math>A</math> be the area of <math>\triangle ABC</math>. Find the remainder when <math>2A</math> is divided by <math>1000</math>. |
− | 12. There exists a line L with points D,E,F with E in between D and F. Point A, not on the line is such that \overline{AF}=6, \overline{AD}=\frac{36}{7}, \overline{AE}=\frac{12}{\sqrt{7}} with \angle AEF > 90. Construct E' on ray AE such that (\overline{AE})(\overline{AE'})=36 and \overline{FE'}=3. Point G is on ray AD such that \overline{AG}=7. If 2*(\overline{E'G})=a+\sqrt{b} where a and b are integers, then find a+b. | + | 12. There exists a line <math>L</math> with points <math>D</math>,<math>E</math>,<math>F</math> with <math>E</math> in between <math>D</math> and <math>F</math>. Point <math>A</math>, not on the line is such that <math>\overline{AF}=6</math>, <math>\overline{AD}=\frac{36}{7}</math>, <math>\overline{AE}=\frac{12}{\sqrt{7}}</math> with <math>\angle AEF > 90</math>. Construct <math>E'</math> on ray <math>AE</math> such that <math>(\overline{AE})(\overline{AE'})=36</math> and <math>\overline{FE'}=3</math>. Point <math>G</math> is on ray <math>AD</math> such that <math>\overline{AG}=7</math>. If <math>2*(\overline{E'G})=a+\sqrt{b}</math> where <math>a</math> and <math>b</math> are integers, then find <math>a+b</math>. |
− | 13. \triangle VA_0A_1 is isosceles with base \overline{{A_1A_0}}. Construct A_2 on segment \overline{{A_0V}} such that \overline{A_0A_1}=\overline{A_1A_2}=b. Construct A_3 on \overline{A_1V} such that b=\overline{A_2A_3}. Contiue this pattern: construct \overline{A_{2n}A_{2n+1}}=b with A_{2n+1} on segment \overline{VA_1} and \overline{A_{2n+1}A_{2n+2}}=b with A_{2n+2} on segment \overline{VA_0}. The points A_n do not coincide and \angle VA_1A_0=90-\frac{1}{2006}. Suppose A_k is the last point you can construct on the perimeter of the triangle. Find the remainder when k is divided by 1000. | + | 13. <math>\triangle VA_0A_1</math> is isosceles with base <math>\overline{{A_1A_0}}</math>. Construct <math>A_2</math> on segment <math>\overline{{A_0V}}</math> such that <math>\overline{A_0A_1}=\overline{A_1A_2}=b</math>. Construct <math>A_3</math> on <math>\overline{A_1V}</math> such that <math>b=\overline{A_2A_3}</math>. Contiue this pattern: construct <math>\overline{A_{2n}A_{2n+1}}=b</math> with <math>A_{2n+1}</math> on segment <math>\overline{VA_1}</math> and <math>\overline{A_{2n+1}A_{2n+2}}=b</math> with <math>A_{2n+2}</math> on segment <math>\overline{VA_0}</math>. The points <math>A_n</math> do not coincide and <math>\angle VA_1A_0=90-\frac{1}{2006}</math>. Suppose <math>A_k</math> is the last point you can construct on the perimeter of the triangle. Find the remainder when <math>k</math> is divided by <math>1000</math>. |
− | 14. P is the probability that if you flip a fair coin, 20 heads will occur before 19 tails. If P=\frac{m}{n} where m and n are relatively prime positive integers, find the remainder when m+n is divided by 1000. | + | 14. <math>P</math> is the probability that if you flip a fair coin, <math>20</math> heads will occur before <math>19</math> tails. If <math>P=\frac{m}{n}</math> where <math>m</math> and <math>n</math> are relatively prime positive integers, find the remainder when <math>m+n</math> is divided by <math>1000</math>. |
− | 15. A regular 61-gon with verticies A_1, A_2, A_3,...A_{61} is inscribed in a circle with a radius of r. Suppose (\overline{A_1A_2})(\overline{A_1A_3})(\overline{A_1A_4})...(\overline{A_1A_{61}})=r. If r^{2006}=\frac{p}{q} where p and q are coprime positive integers, find the remainder when p+q is divided by 1000. | + | 15. A regular 61-gon with verticies <math>A_1</math>, <math>A_2</math>, <math>A_3</math>,...<math>A_{61}</math> is inscribed in a circle with a radius of <math>r</math>. Suppose <math>(\overline{A_1A_2})(\overline{A_1A_3})(\overline{A_1A_4})...(\overline{A_1A_{61}})=r</math>. If <math>r^{2006}=\frac{p}{q}</math> where <math>p</math> and <math>q</math> are coprime positive integers, find the remainder when <math>p+q</math> is divided by <math>1000</math>. |
[http://www.artofproblemsolving.com/Forum/viewtopic.php?t=70988 Here is the page on AoPS] | [http://www.artofproblemsolving.com/Forum/viewtopic.php?t=70988 Here is the page on AoPS] |
Revision as of 03:40, 26 February 2007
Contents
[hide]Problem 1
Suppose is a positive integer. Let be the sum of the distinct positive prime divisors of less than (e.g. and ). Evaluate the remainder when is divided by .
Problem 2
A circle of radius is internally tangent to a larger circle of radius such that the center of lies on . A diameter of is drawn tangent to . A second line is drawn from tangent to . Let the line tangent to at intersect at . Find the area of .
Problem 3
A number , where denotes the th digit in the base- representation of for , is a positive integer with distinct nonzero digits such that if is even and if is odd for (and ). Let be the number of four-digit hailstone numbers and be the number of three-digit hailstone numbers. Find .
Problem 4
Let and be integers such that and . Given that and , find the number of ordered pairs such that . ( is the greatest integer less than or equal to and is the least integer greater than or equal to ).
Problem 5
Find the largest prime divisor of .
Problem 6
, , and are polynomials defined by:
Find the number of distinct complex roots of .
Problem 7
A coin of radius is flipped onto an square grid divided into equal squares. Circles are inscribed in of these squares. Let be the probability that, given that the coin lands completely within one of the smaller squares, it also lands completely within one of the circles. Let be the probability that, when flipped onto the grid, the coin lands completely within one of the smaller squares. Let smallest value of such that . Find the value of .
Problem 8
Let be a polyhedron with faces, all of which are equilateral triangles, squares, or regular pentagons with equal side length. Given there is at least one of each type of face and there are twice as many pentagons as triangles, what is the sum of all the possible number of vertices can have?
Problem 9
nondistinguishable residents are moving into distinct houses in Conformistville, with at least one resident per house. In how many ways can the residents be assigned to these houses such that there is at least one house with residents?
Problem 10
Find the smallest positive integer such that is divisible by all the primes between and .
Problem 11
Let be a subset of consecutive elements of where is a positive integer. Define , where if has an odd number of divisors and if has an even number of divisors. For how many does there exist an such that and ? ( denotes the cardinality of the set , or the number of elements in )
Problem 12
Let be a triangle with , , and . Let be the foot of the altitude from to and be the point on between and such that . Extend to meet the circumcircle of at . If the area of triangle is , where and are relatively prime positive integers, find .
Problem 13
Let be the set of positive integers with only odd digits satisfying the following condition: any with digits must be divisible by . Let be the sum of the smallest elements of . Find the remainder upon dividing by .
Problem 14
Let be a triangle such that , , and . Let be the orthocenter of (intersection of the altitudes). Let be the midpoint of , be the midpoint of , and be the midpoint of . Points , , and are constructed on , , and , respectively, such that is the midpoint of , is the midpoint of , and is the midpoint of . Find .
Problem 15
colored beads are placed on a necklace (circular ring) such that each bead is adjacent to two others. The beads are labeled , , , around the circle in order. Two beads and , where and are non-negative integers, satisfy if and only if the color of is the same as the color of . Given that there exists no non-negative integer and positive integer such that , where all subscripts are taken , find the minimum number of different colors of beads on the necklace.
See also
- Mock AIME 5 2005-2006
- Mock AIME
- A .pdf version of the problems
http://www.mathlinks.ro/Forum/latexrender/pictures/2ea0ce047615395691113a82d6c190b3.gif
1. A 5-digit number is leet if and only if the sum of the first 2 digits, the sum of the last 2 digits and the middle digit are equal. How many 5-digit leet numbers exist?
2. Qin Shi Huang wants to count the number of warriors he has to invade China. He puts his warriors into lines with the most people such that they have even length. The people left over are the remainder. He makes 2 lines, with a remainder of 1, 3 lines with a remainder of 2, 4 lines with a remainder of 3, 5 lines with a remainder of 4, and 6 lines with a remainder of 5. Find the minimum number of warriors that he has.
3. is a regular tetrahedron. Tetrahedron is formed by connecting the centers of the faces of . Generally, a new tetrahedron is formed by connecting the centers of the faces of . is the volume of tetrahedron . where and are coprime positive integers, find the remainder when is divided by .
4. Let . Let be the product of the roots. How many digits are does have where denotes the greatest integer less than or equal to ?
5. A parabola is rotated degrees clockwise about the origin to . This image is translated upward to . Point , , and is in Quadrant I, on . If the area of is at a maximum, it is where , and are integers and is square free, find .
6. Define a sequence and for all positive integers . Find the remainder when is divided by .
7. is a function that satisfies for all defined . Suppose that the sum of the zeros of where and are coprime positive integers, find .
8. is a solution to . Suppose that find where is the greatest integer less than or equal to .
9. Zeus, Athena, and Posideon arrive at Mount Olympus at a random time between 12:00 pm and 12:00 am, and stay for 3 hours. All three hours does not need to fall within 12 pm to 12 am. If any of the 2 gods see each other during 12 pm to 12 am, it will be a good day. The probability of it being a good day is where and are coprime positive integers, find .
10. Define . Find the remainder when is divided by .
11. is isosceles with . A point lies inside the triangle such that , , and . Let be the area of . Find the remainder when is divided by .
12. There exists a line with points ,, with in between and . Point , not on the line is such that , , with . Construct on ray such that and . Point is on ray such that . If where and are integers, then find .
13. is isosceles with base . Construct on segment such that . Construct on such that . Contiue this pattern: construct with on segment and with on segment . The points do not coincide and . Suppose is the last point you can construct on the perimeter of the triangle. Find the remainder when is divided by .
14. is the probability that if you flip a fair coin, heads will occur before tails. If where and are relatively prime positive integers, find the remainder when is divided by .
15. A regular 61-gon with verticies , , ,... is inscribed in a circle with a radius of . Suppose . If where and are coprime positive integers, find the remainder when is divided by .