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 | ||
Line 24: | Line 25: | ||
different type of flower. The lengths, in feet, of the rectangular regions in her | 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 | flower bed are as shown in the figure. She plants one flower per square foot in | ||
− | each region. Asters cost | + | 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? | for her garden? | ||
Line 46: | Line 47: | ||
== 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]] | ||
Line 89: | Line 150: | ||
== 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]] | ||
Line 101: | Line 176: | ||
of equal length, as shown. What is the area of the shaded region that lies within | of equal length, as shown. What is the area of the shaded region that lies within | ||
the large semicircle but outside the smaller semicircles? | 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> | <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> | ||
Line 116: | Line 221: | ||
[[2003 AMC 12B Problems/Problem 17|Solution]] | [[2003 AMC 12B Problems/Problem 17|Solution]] | ||
+ | |||
+ | |||
+ | |||
+ | == Problem 18 == | ||
+ | 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>\textbf{(A)}\ 30 \qquad \textbf{(B)}\ 31 \qquad \textbf{(C)}\ 32 \qquad \textbf{(D)}\ 33 \qquad \textbf{(E)}\ 34</math> | ||
+ | |||
+ | [[2003 AMC 12B Problems/Problem 18|Solution]] | ||
== Problem 19 == | == Problem 19 == | ||
Line 152: | Line 266: | ||
[[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 206: | Line 320: | ||
== Problem 25 == | == Problem 25 == | ||
− | Three points are chosen randomly and independently on a circle. What is the probability that all three pairwise | + | 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} | <math>\mathrm{(A)}\ \dfrac{1}{36} | ||
Line 217: | Line 331: | ||
== 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 17:53, 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?
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 ?
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
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.