Difference between revisions of "2003 AMC 12B Problems"
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+ | {{AMC12 Problems|year=2003|ab=B}} | ||
== Problem 1 == | == Problem 1 == | ||
Which of the following is the same as | Which of the following is the same as | ||
− | <cmath>\frac{2-4+6-8+10-12+14}{3-6+9-12+15-18+21}</cmath> | + | <cmath>\frac{2-4+6-8+10-12+14}{3-6+9-12+15-18+21}?</cmath> |
<math> | <math> | ||
Line 11: | Line 12: | ||
== Problem 2 == | == Problem 2 == | ||
+ | Al gets the disease algebritis and must take one green pill and one pink pill each day for two weeks. A green pill costs 1 dollar more than a pink pill, and Al's pills cost a total of 546 dollars for the two weeks. How much does one green pill cost? | ||
+ | |||
+ | <math> | ||
+ | \text {(A) } 7 \qquad \text {(B) } 14 \qquad \text {(C) } 19 \qquad \text {(D) } 20 \qquad \text {(E) } 39 | ||
+ | </math> | ||
[[2003 AMC 12B Problems/Problem 2|Solution]] | [[2003 AMC 12B Problems/Problem 2|Solution]] | ||
== Problem 3 == | == Problem 3 == | ||
+ | |||
+ | Rose fills each of the rectangular regions of her rectangular flower bed with a | ||
+ | different type of flower. The lengths, in feet, of the rectangular regions in her | ||
+ | flower bed are as shown in the figure. She plants one flower per square foot in | ||
+ | each region. Asters cost \$1 each, begonias \$1.50 each, cannas \$2 each, dahlias | ||
+ | \$2.50 each, and Easter lilies \$3 each. What is the least possible cost, in dollars, | ||
+ | for her garden? | ||
+ | |||
+ | [[File:problem_3.png]] | ||
+ | |||
+ | <math> | ||
+ | \text {(A) } 108 \qquad \text {(B) } 115 \qquad \text {(C) } 132 \qquad \text {(D) } 144 \qquad \text {(E) } 156 | ||
+ | </math> | ||
[[2003 AMC 12B Problems/Problem 3|Solution]] | [[2003 AMC 12B Problems/Problem 3|Solution]] | ||
== Problem 4 == | == Problem 4 == | ||
+ | Moe uses a mower to cut his rectangular 90-foot by 150-foot lawn. The swath he cuts is 28 inches wide, but he overlaps each cut by 4 inches to make sure that no grass is missed. he walks at the rate of 5000 feet per hour while pushing the mower. Which of the following is closest to the number of hours it will take Moe to mow his lawn? | ||
+ | |||
+ | <math> | ||
+ | \text {(A) } 0.75 \qquad \text {(B) } 0.8 \qquad \text {(C) } 1.35 \qquad \text {(D) } 1.5 \qquad \text {(E) } 3 | ||
+ | </math> | ||
[[2003 AMC 12B Problems/Problem 4|Solution]] | [[2003 AMC 12B Problems/Problem 4|Solution]] | ||
== Problem 5 == | == Problem 5 == | ||
+ | Many television screens are rectangles that are measured by the length of their diagonals. The ratio of the horizontal length to the height in a standard television screen is 4 : 3. The horizontal length of a "27-inch" television screen is closest, in inches, to which of the following? | ||
+ | |||
+ | [[File:Problem_5.PNG]] | ||
+ | |||
+ | <math> | ||
+ | \text {(A) } 20 \qquad \text {(B) } 20.5 \qquad \text {(C) } 21 \qquad \text {(D) } 21.5 \qquad \text {(E) } 22 | ||
+ | </math> | ||
[[2003 AMC 12B Problems/Problem 5|Solution]] | [[2003 AMC 12B Problems/Problem 5|Solution]] | ||
== Problem 6 == | == Problem 6 == | ||
+ | The second and fourth terms of a geometric sequence are 2 and 6. Which of the following is a possible first term? | ||
+ | |||
+ | <math> | ||
+ | \text {(A) } -\sqrt{3} \qquad \text {(B) } \frac{-2\sqrt{3}}{3} \qquad \text {(C) } \frac{-\sqrt{3}}{3} \qquad \text {(D) } \sqrt{3} \qquad \text {(E) } 3 | ||
+ | </math> | ||
[[2003 AMC 12B Problems/Problem 6|Solution]] | [[2003 AMC 12B Problems/Problem 6|Solution]] | ||
== Problem 7 == | == Problem 7 == | ||
+ | Penniless Pete's piggy bank has no pennies in it, but it has 100 coins, all nickels, dimes, and quarters, whose total value is \$8.35. It does not necessarily contain coins of all three types. What is the difference between the largest and smallest number of dimes that could be in the bank? | ||
+ | |||
+ | <math> | ||
+ | \text {(A) } 0 \qquad \text {(B) } 13 \qquad \text {(C) } 37 \qquad \text {(D) } 64 \qquad \text {(E) } 83 | ||
+ | </math> | ||
[[2003 AMC 12B Problems/Problem 7|Solution]] | [[2003 AMC 12B Problems/Problem 7|Solution]] | ||
== Problem 8 == | == Problem 8 == | ||
+ | |||
+ | Let <math>\clubsuit(x)</math> denote the sum of the digits of the positive integer <math>x</math>. For example, <math>\clubsuit(8) = 8</math> and <math>\clubsuit(123) = 1 + 2 + 3 = 6.</math> For how many two-digit values of <math>x</math> is <math>\clubsuit(\clubsuit(x)) = 3?</math> | ||
+ | |||
+ | <math> \text{(A) }3\qquad\text{(B) }4\qquad\text{(C) }6\qquad\text{(D) }9\qquad\text{(E) }10 </math> | ||
[[2003 AMC 12B Problems/Problem 8|Solution]] | [[2003 AMC 12B Problems/Problem 8|Solution]] | ||
== Problem 9 == | == Problem 9 == | ||
+ | Let <math>f</math> be a linear function for which <math>f(6) - f(2) = 12.</math> What is <math>f(12) - f(2)?</math> | ||
+ | |||
+ | <math> | ||
+ | \text {(A) } 12 \qquad \text {(B) } 18 \qquad \text {(C) } 24 \qquad \text {(D) } 30 \qquad \text {(E) } 36 | ||
+ | </math> | ||
[[2003 AMC 12B Problems/Problem 9|Solution]] | [[2003 AMC 12B Problems/Problem 9|Solution]] | ||
== Problem 10 == | == Problem 10 == | ||
+ | Several figures can be made by attaching two equilateral triangles to the regular pentagon ABCDE in two of the five positions shown. How many non-congruent figures can be constructed in this way? | ||
+ | <center><asy> | ||
+ | size(200); | ||
+ | defaultpen(0.9); | ||
+ | real r = 5/dir(54).x, h = 5 tan(54*pi/180); | ||
+ | pair A = (5,0), B = A+10*dir(72), C = (0,r+h), E = (-5,0), D = E+10*dir(108); | ||
+ | draw(A--B--C--D--E--cycle); | ||
+ | label("\(A\)",A+(0,-0.5),SSE); | ||
+ | label("\(B\)",B+(0.5,0),ENE); | ||
+ | label("\(C\)",C+(0,0.5),N); | ||
+ | label("\(D\)",D+(-0.5,0),WNW); | ||
+ | label("\(E\)",E+(0,-0.5),SW); | ||
+ | // | ||
+ | real l = 5*sqrt(3); pair ab = (h+l)*dir(72), bc = (h+l)*dir(54); | ||
+ | pair AB = (ab.y, h-ab.x), BC = (bc.x,h+bc.y), CD = (-bc.x,h+bc.y), DE = (-ab.y, h-ab.x), EA = (0,-l); | ||
+ | draw(A--AB--B^^B--BC--C^^C--CD--D^^D--DE--E^^E--EA--A, dashed); | ||
+ | // | ||
+ | dot(A); dot(B); dot(C); dot(D); dot(E); dot(AB); dot(BC); dot(CD); dot(DE); dot(EA); | ||
+ | </asy></center> | ||
+ | |||
+ | <math> | ||
+ | \text {(A) } 1 \qquad \text {(B) } 2 \qquad \text {(C) } 3 \qquad \text {(D) } 4 \qquad \text {(E) } 5 | ||
+ | </math> | ||
[[2003 AMC 12B Problems/Problem 10|Solution]] | [[2003 AMC 12B Problems/Problem 10|Solution]] | ||
== Problem 11 == | == Problem 11 == | ||
+ | Cassandra sets her watch to the correct time at noon. At the actual time of 1:00 PM, she notices that her watch reads 12:57 and 36 seconds. Assuming that her watch loses time at a constant rate, what will be the actual time when her | ||
+ | watch first reads 10:00 PM? | ||
+ | |||
+ | <math> | ||
+ | \text {(A) 10:22 PM and 24 seconds} \qquad \text {(B) 10:24 PM} \qquad \text {(C) 10:25 PM} \qquad \text {(D) 10:27 PM} \qquad \text {(E) 10:30 PM} | ||
+ | </math> | ||
[[2003 AMC 12B Problems/Problem 11|Solution]] | [[2003 AMC 12B Problems/Problem 11|Solution]] | ||
== Problem 12 == | == Problem 12 == | ||
+ | What is the largest integer that is a divisor of <math>(n+1)(n+3)(n+5)(n+7)(n+9)</math> for all positive even integers <math>n</math>? | ||
+ | |||
+ | <math> | ||
+ | \text {(A) } 3 \qquad \text {(B) } 5 \qquad \text {(C) } 11 \qquad \text {(D) } 15 \qquad \text {(E) } 165 | ||
+ | </math> | ||
[[2003 AMC 12B Problems/Problem 12|Solution]] | [[2003 AMC 12B Problems/Problem 12|Solution]] | ||
== Problem 13 == | == Problem 13 == | ||
+ | An ice cream [[cone]] consists of a [[sphere]] of vanilla ice cream and a right circular cone that has the same diameter as the sphere. If the ice cream melts, it will exactly fill the cone. Assume that the melted ice cream occupies <math>75\%</math> of the volume of the frozen ice cream. What is the ratio of the cone’s height to its [[radius]]? | ||
+ | |||
+ | <math>\mathrm{(A)}\ 2:1 | ||
+ | \qquad\mathrm{(B)}\ 3:1 | ||
+ | \qquad\mathrm{(C)}\ 4:1 | ||
+ | \qquad\mathrm{(D)}\ 16:3 | ||
+ | \qquad\mathrm{(E)}\ 6:1</math> | ||
[[2003 AMC 12B Problems/Problem 13|Solution]] | [[2003 AMC 12B Problems/Problem 13|Solution]] | ||
== Problem 14 == | == Problem 14 == | ||
+ | In rectangle <math>ABCD, AB=5</math> and <math>BC=3</math>. Points <math>F</math> and <math>G</math> are on <math>\overline{CD}</math> so that <math>DF=1</math> and <math>GC=2</math>. Lines <math>AF</math> and <math>BG</math> intersect at <math>E</math>. Find the area of <math>\triangle AEB</math>. | ||
+ | |||
+ | [[File:Problem_14.png]] | ||
+ | |||
+ | <math> | ||
+ | \text {(A) } 10 \qquad \text {(B) } \frac{21}{2} \qquad \text {(C) } 12 \qquad \text {(D) } \frac{25}{2} \qquad \text {(E) } 15 | ||
+ | </math> | ||
[[2003 AMC 12B Problems/Problem 14|Solution]] | [[2003 AMC 12B Problems/Problem 14|Solution]] | ||
== Problem 15 == | == Problem 15 == | ||
+ | A regular octagon <math>ABCDEFGH</math> has an area of one square unit. What is the area of the rectangle <math>ABEF</math>? | ||
+ | |||
+ | [[File:Problem_15.PNG]] | ||
+ | |||
+ | <math> | ||
+ | \text {(A) } 1-\frac{\sqrt{2}}{2} \qquad \text {(B) } \frac{\sqrt{2}}{4} \qquad \text {(C) } \sqrt{2}-1 \qquad \text {(D) } \frac{1}{2} \qquad \text {(E) } \frac{1+\sqrt{2}}{4} | ||
+ | </math> | ||
[[2003 AMC 12B Problems/Problem 15|Solution]] | [[2003 AMC 12B Problems/Problem 15|Solution]] | ||
== Problem 16 == | == Problem 16 == | ||
+ | Three semicircles of radius 1 are constructed on diameter AB of a semicircle of | ||
+ | radius 2. The centers of the small semicircles divide AB into four line segments | ||
+ | of equal length, as shown. What is the area of the shaded region that lies within | ||
+ | the large semicircle but outside the smaller semicircles? | ||
+ | |||
+ | <asy> | ||
+ | import graph; | ||
+ | unitsize(14mm); | ||
+ | defaultpen(linewidth(.8pt)+fontsize(8pt)); | ||
+ | dashed=linetype("4 4"); | ||
+ | dotfactor=3; | ||
+ | pair A=(-2,0), B=(2,0); | ||
+ | fill(Arc((0,0),2,0,180)--cycle,mediumgray); | ||
+ | fill(Arc((-1,0),1,0,180)--cycle,white); | ||
+ | fill(Arc((0,0),1,0,180)--cycle,white); | ||
+ | fill(Arc((1,0),1,0,180)--cycle,white); | ||
+ | draw(Arc((-1,0),1,60,180)); | ||
+ | draw(Arc((0,0),1,0,60),dashed); | ||
+ | draw(Arc((0,0),1,60,120)); | ||
+ | draw(Arc((0,0),1,120,180),dashed); | ||
+ | draw(Arc((1,0),1,0,120)); | ||
+ | draw(Arc((0,0),2,0,180)--cycle); | ||
+ | dot((0,0)); | ||
+ | dot((-1,0)); | ||
+ | dot((1,0)); | ||
+ | draw((-2,-0.1)--(-2,-0.3),gray); | ||
+ | draw((-1,-0.1)--(-1,-0.3),gray); | ||
+ | draw((1,-0.1)--(1,-0.3),gray); | ||
+ | draw((2,-0.1)--(2,-0.3),gray); | ||
+ | label("$A$",A,W); | ||
+ | label("$B$",B,E); | ||
+ | label("1",(-1.5,-0.1),S); | ||
+ | label("2",(0,-0.1),S); | ||
+ | label("1",(1.5,-0.1),S);</asy> | ||
+ | |||
+ | <math>\textbf{(A) } \pi - \sqrt{3} \qquad\textbf{(B) } \pi - \sqrt{2} \qquad\textbf{(C) } \frac{\pi + \sqrt{2}}{2} \qquad\textbf{(D) } \frac{\pi +\sqrt{3}}{2} \qquad\textbf{(E) } \frac{7}{6}\pi - \frac{\sqrt{3}}{2}</math> | ||
[[2003 AMC 12B Problems/Problem 16|Solution]] | [[2003 AMC 12B Problems/Problem 16|Solution]] | ||
== Problem 17 == | == Problem 17 == | ||
+ | If <math>\log (xy^3) = 1</math> and <math>\log (x^2y) = 1</math>, what is <math>\log (xy)</math>? | ||
+ | |||
+ | <math>\mathrm{(A)}\ -\frac 12 | ||
+ | \qquad\mathrm{(B)}\ 0 | ||
+ | \qquad\mathrm{(C)}\ \frac 12 | ||
+ | \qquad\mathrm{(D)}\ \frac 35 | ||
+ | \qquad\mathrm{(E)}\ 1</math> | ||
[[2003 AMC 12B Problems/Problem 17|Solution]] | [[2003 AMC 12B Problems/Problem 17|Solution]] | ||
+ | |||
+ | |||
== Problem 18 == | == Problem 18 == | ||
− | Let <math> | + | Let <math>x</math> and <math>y</math> be positive integers such that <math>7x^5 = 11y^{13}.</math> The minimum possible value of <math>x</math> has a prime factorization <math>a^cb^d.</math> What is <math>a + b + c + d</math>? |
− | <math> | + | <math>\textbf{(A)}\ 30 \qquad \textbf{(B)}\ 31 \qquad \textbf{(C)}\ 32 \qquad \textbf{(D)}\ 33 \qquad \textbf{(E)}\ 34</math> |
− | \ | ||
− | </math> | ||
[[2003 AMC 12B Problems/Problem 18|Solution]] | [[2003 AMC 12B Problems/Problem 18|Solution]] | ||
Line 95: | Line 243: | ||
== Problem 20 == | == Problem 20 == | ||
+ | Part of the graph of <math>f(x) = ax^3 + bx^2 + cx + d</math> is shown. What is <math>b</math>? | ||
+ | |||
+ | [[Image:2003_12B_AMC-20.png]] | ||
+ | |||
+ | <math>\mathrm{(A)}\ -4 | ||
+ | \qquad\mathrm{(B)}\ -2 | ||
+ | \qquad\mathrm{(C)}\ 0 | ||
+ | \qquad\mathrm{(D)}\ 2 | ||
+ | \qquad\mathrm{(E)}\ 4</math> | ||
[[2003 AMC 12B Problems/Problem 20|Solution]] | [[2003 AMC 12B Problems/Problem 20|Solution]] | ||
Line 101: | Line 258: | ||
An object moves <math>8</math> cm in a straight [[line]] from <math>A</math> to <math>B</math>, turns at an angle <math>\alpha</math>, measured in radians and chosen at random from the interval <math>(0,\pi)</math>, and moves <math>5</math> cm in a straight line to <math>C</math>. What is the [[probability]] that <math>AC < 7</math>? | An object moves <math>8</math> cm in a straight [[line]] from <math>A</math> to <math>B</math>, turns at an angle <math>\alpha</math>, measured in radians and chosen at random from the interval <math>(0,\pi)</math>, and moves <math>5</math> cm in a straight line to <math>C</math>. What is the [[probability]] that <math>AC < 7</math>? | ||
− | <math>\mathrm{(A)}\ | + | <math>\mathrm{(A)}\ \frac{1}{6} |
− | \qquad\mathrm{(B)}\ | + | \qquad\mathrm{(B)}\ \frac{1}{5} |
− | \qquad\mathrm{(C)}\ | + | \qquad\mathrm{(C)}\ \frac{1}{4} |
− | \qquad\mathrm{(D)}\ | + | \qquad\mathrm{(D)}\ \frac{1}{3} |
− | \qquad\mathrm{(E)}\ | + | \qquad\mathrm{(E)}\ \frac{1}{2}</math> |
[[2003 AMC 12B Problems/Problem 21|Solution]] | [[2003 AMC 12B Problems/Problem 21|Solution]] | ||
== Problem 22 == | == Problem 22 == | ||
− | |||
Let <math>ABCD</math> be a [[rhombus]] with <math>AC = 16</math> and <math>BD = 30</math>. Let <math>N</math> be a point on <math>\overline{AB}</math>, and let <math>P</math> and <math>Q</math> be the feet of the perpendiculars from <math>N</math> to <math>\overline{AC}</math> and <math>\overline{BD}</math>, respectively. Which of the following is closest to the minimum possible value of <math>PQ</math>? | Let <math>ABCD</math> be a [[rhombus]] with <math>AC = 16</math> and <math>BD = 30</math>. Let <math>N</math> be a point on <math>\overline{AB}</math>, and let <math>P</math> and <math>Q</math> be the feet of the perpendiculars from <math>N</math> to <math>\overline{AC}</math> and <math>\overline{BD}</math>, respectively. Which of the following is closest to the minimum possible value of <math>PQ</math>? | ||
Line 140: | Line 296: | ||
== Problem 23 == | == Problem 23 == | ||
+ | The number of <math>x</math>-intercepts on the graph of <math>y=\sin(1/x)</math> in the interval <math>(0.0001,0.001)</math> is closest to | ||
+ | |||
+ | <math>\mathrm{(A)}\ 2900 | ||
+ | \qquad\mathrm{(B)}\ 3000 | ||
+ | \qquad\mathrm{(C)}\ 3100 | ||
+ | \qquad\mathrm{(D)}\ 3200 | ||
+ | \qquad\mathrm{(E)}\ 3300</math> | ||
[[2003 AMC 12B Problems/Problem 23|Solution]] | [[2003 AMC 12B Problems/Problem 23|Solution]] | ||
== Problem 24 == | == Problem 24 == | ||
+ | Positive integers <math>a,b,</math> and <math>c</math> are chosen so that <math>a<b<c</math>, and the system of [[equation]]s | ||
+ | <center><math>2x + y = 2003 \quad</math> and <math>\quad y = |x-a| + |x-b| + |x-c|</math></center> | ||
+ | has exactly one solution. What is the minimum value of <math>c</math>? | ||
+ | |||
+ | <math>\mathrm{(A)}\ 668 | ||
+ | \qquad\mathrm{(B)}\ 669 | ||
+ | \qquad\mathrm{(C)}\ 1002 | ||
+ | \qquad\mathrm{(D)}\ 2003 | ||
+ | \qquad\mathrm{(E)}\ 2004</math> | ||
[[2003 AMC 12B Problems/Problem 24|Solution]] | [[2003 AMC 12B Problems/Problem 24|Solution]] | ||
== Problem 25 == | == Problem 25 == | ||
+ | Three points are chosen randomly and independently on a circle. What is the probability that all three pairwise distances between the points are less than the radius of the circle? | ||
+ | |||
+ | <math>\mathrm{(A)}\ \dfrac{1}{36} | ||
+ | \qquad\mathrm{(B)}\ \dfrac{1}{24} | ||
+ | \qquad\mathrm{(C)}\ \dfrac{1}{18} | ||
+ | \qquad\mathrm{(D)}\ \dfrac{1}{12} | ||
+ | \qquad\mathrm{(E)}\ \dfrac{1}{9}</math> | ||
[[2003 AMC 12B Problems/Problem 25|Solution]] | [[2003 AMC 12B Problems/Problem 25|Solution]] | ||
== See also == | == See also == | ||
+ | |||
+ | {{AMC12 box|year=2003|ab=B|before=[[2003 AMC 12A Problems]]|after=[[2004 AMC 12A Problems]]}} | ||
+ | |||
* [[AMC 12]] | * [[AMC 12]] | ||
* [[AMC 12 Problems and Solutions]] | * [[AMC 12 Problems and Solutions]] | ||
* [[2003 AMC 12B]] | * [[2003 AMC 12B]] | ||
* [[Mathematics competition resources]] | * [[Mathematics competition resources]] | ||
+ | {{MAA Notice}} |
Latest revision as of 18:53, 10 December 2022
2003 AMC 12B (Answer Key) Printable versions: • AoPS Resources • PDF | ||
Instructions
| ||
1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22 • 23 • 24 • 25 |
Contents
- 1 Problem 1
- 2 Problem 2
- 3 Problem 3
- 4 Problem 4
- 5 Problem 5
- 6 Problem 6
- 7 Problem 7
- 8 Problem 8
- 9 Problem 9
- 10 Problem 10
- 11 Problem 11
- 12 Problem 12
- 13 Problem 13
- 14 Problem 14
- 15 Problem 15
- 16 Problem 16
- 17 Problem 17
- 18 Problem 18
- 19 Problem 19
- 20 Problem 20
- 21 Problem 21
- 22 Problem 22
- 23 Problem 23
- 24 Problem 24
- 25 Problem 25
- 26 See also
Problem 1
Which of the following is the same as
Problem 2
Al gets the disease algebritis and must take one green pill and one pink pill each day for two weeks. A green pill costs 1 dollar more than a pink pill, and Al's pills cost a total of 546 dollars for the two weeks. How much does one green pill cost?
Problem 3
Rose fills each of the rectangular regions of her rectangular flower bed with a different type of flower. The lengths, in feet, of the rectangular regions in her flower bed are as shown in the figure. She plants one flower per square foot in each region. Asters cost $1 each, begonias $1.50 each, cannas $2 each, dahlias $2.50 each, and Easter lilies $3 each. What is the least possible cost, in dollars, for her garden?
Problem 4
Moe uses a mower to cut his rectangular 90-foot by 150-foot lawn. The swath he cuts is 28 inches wide, but he overlaps each cut by 4 inches to make sure that no grass is missed. he walks at the rate of 5000 feet per hour while pushing the mower. Which of the following is closest to the number of hours it will take Moe to mow his lawn?
Problem 5
Many television screens are rectangles that are measured by the length of their diagonals. The ratio of the horizontal length to the height in a standard television screen is 4 : 3. The horizontal length of a "27-inch" television screen is closest, in inches, to which of the following?
Problem 6
The second and fourth terms of a geometric sequence are 2 and 6. Which of the following is a possible first term?
Problem 7
Penniless Pete's piggy bank has no pennies in it, but it has 100 coins, all nickels, dimes, and quarters, whose total value is $8.35. It does not necessarily contain coins of all three types. What is the difference between the largest and smallest number of dimes that could be in the bank?
Problem 8
Let denote the sum of the digits of the positive integer
. For example,
and
For how many two-digit values of
is
Problem 9
Let be a linear function for which
What is
Problem 10
Several figures can be made by attaching two equilateral triangles to the regular pentagon ABCDE in two of the five positions shown. How many non-congruent figures can be constructed in this way?
![[asy] size(200); defaultpen(0.9); real r = 5/dir(54).x, h = 5 tan(54*pi/180); pair A = (5,0), B = A+10*dir(72), C = (0,r+h), E = (-5,0), D = E+10*dir(108); draw(A--B--C--D--E--cycle); label("\(A\)",A+(0,-0.5),SSE); label("\(B\)",B+(0.5,0),ENE); label("\(C\)",C+(0,0.5),N); label("\(D\)",D+(-0.5,0),WNW); label("\(E\)",E+(0,-0.5),SW); // real l = 5*sqrt(3); pair ab = (h+l)*dir(72), bc = (h+l)*dir(54); pair AB = (ab.y, h-ab.x), BC = (bc.x,h+bc.y), CD = (-bc.x,h+bc.y), DE = (-ab.y, h-ab.x), EA = (0,-l); draw(A--AB--B^^B--BC--C^^C--CD--D^^D--DE--E^^E--EA--A, dashed); // dot(A); dot(B); dot(C); dot(D); dot(E); dot(AB); dot(BC); dot(CD); dot(DE); dot(EA); [/asy]](http://latex.artofproblemsolving.com/a/3/b/a3b1113e62996ab9b1c6c83bc4836bbb32070801.png)
Problem 11
Cassandra sets her watch to the correct time at noon. At the actual time of 1:00 PM, she notices that her watch reads 12:57 and 36 seconds. Assuming that her watch loses time at a constant rate, what will be the actual time when her watch first reads 10:00 PM?
Problem 12
What is the largest integer that is a divisor of for all positive even integers
?
Problem 13
An ice cream cone consists of a sphere of vanilla ice cream and a right circular cone that has the same diameter as the sphere. If the ice cream melts, it will exactly fill the cone. Assume that the melted ice cream occupies of the volume of the frozen ice cream. What is the ratio of the cone’s height to its radius?
Problem 14
In rectangle and
. Points
and
are on
so that
and
. Lines
and
intersect at
. Find the area of
.
Problem 15
A regular octagon has an area of one square unit. What is the area of the rectangle
?
Problem 16
Three semicircles of radius 1 are constructed on diameter AB of a semicircle of radius 2. The centers of the small semicircles divide AB into four line segments of equal length, as shown. What is the area of the shaded region that lies within the large semicircle but outside the smaller semicircles?
Problem 17
If and
, what is
?
Problem 18
Let and
be positive integers such that
The minimum possible value of
has a prime factorization
What is
?
Problem 19
Let be the set of permutations of the sequence
for which the first term is not
. A permutation is chosen randomly from
. The probability that the second term is
, in lowest terms, is
. What is
?
Problem 20
Part of the graph of is shown. What is
?
Problem 21
An object moves cm in a straight line from
to
, turns at an angle
, measured in radians and chosen at random from the interval
, and moves
cm in a straight line to
. What is the probability that
?
Problem 22
Let be a rhombus with
and
. Let
be a point on
, and let
and
be the feet of the perpendiculars from
to
and
, respectively. Which of the following is closest to the minimum possible value of
?
![[asy] size(200); defaultpen(0.6); pair O = (15*15/17,8*15/17), C = (17,0), D = (0,0), P = (25.6,19.2), Q = (25.6, 18.5); pair A = 2*O-C, B = 2*O-D; pair P = (A+O)/2, Q=(B+O)/2, N=(A+B)/2; draw(A--B--C--D--cycle); draw(A--O--B--O--C--O--D); draw(P--N--Q); label("\(A\)",A,WNW); label("\(B\)",B,ESE); label("\(C\)",C,ESE); label("\(D\)",D,SW); label("\(P\)",P,SSW); label("\(Q\)",Q,SSE); label("\(N\)",N,NNE); [/asy]](http://latex.artofproblemsolving.com/c/2/2/c22d4d20155faaf8bd0cf51f26a5795d14b32322.png)
Problem 23
The number of -intercepts on the graph of
in the interval
is closest to
Problem 24
Positive integers and
are chosen so that
, and the system of equations
![$2x + y = 2003 \quad$](http://latex.artofproblemsolving.com/7/0/6/706aa31c279b4f4744165bfddf5f8bd451518a57.png)
![$\quad y = |x-a| + |x-b| + |x-c|$](http://latex.artofproblemsolving.com/5/7/c/57c363455cd9e9bf8c2dceadb7298327d953e0bc.png)
has exactly one solution. What is the minimum value of ?
Problem 25
Three points are chosen randomly and independently on a circle. What is the probability that all three pairwise distances between the points are less than the radius of the circle?
See also
2003 AMC 12B (Problems • Answer Key • Resources) | |
Preceded by 2003 AMC 12A Problems |
Followed by 2004 AMC 12A Problems |
1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22 • 23 • 24 • 25 | |
All AMC 12 Problems and Solutions |
The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions.