Difference between revisions of "2014 AMC 12A Problems"
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+ | {{AMC12 Problems|year=2014|ab=A}} | ||
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==Problem 1== | ==Problem 1== | ||
What is <math>10 \cdot \left(\tfrac{1}{2} + \tfrac{1}{5} + \tfrac{1}{10}\right)^{-1}?</math> | What is <math>10 \cdot \left(\tfrac{1}{2} + \tfrac{1}{5} + \tfrac{1}{10}\right)^{-1}?</math> | ||
− | <math> \textbf{(A)}\ 3\qquad\textbf{(B)}\ 8\qquad\textbf{(C)}\ \frac{25}{2}\qquad\textbf{(D) | + | <math> \textbf{(A)}\ 3\qquad\textbf{(B)}\ 8\qquad\textbf{(C)}\ \frac{25}{2}\qquad\textbf{(D)}\ \frac{170}{3}\qquad\textbf{(E)}\ 170</math> |
− | [[2014 AMC | + | [[2014 AMC 10A Problems/Problem 1|Solution]] |
==Problem 2== | ==Problem 2== | ||
− | At the theater children get in for half price. The price for <math>5</math> adult tickets and <math>4</math> child tickets is <math>24.50</math>. How much would <math>8</math> adult tickets and <math>6</math> child tickets cost? | + | At the theater children get in for half price. The price for <math>5</math> adult tickets and <math>4</math> child tickets is <math>$24.50</math>. How much would <math>8</math> adult tickets and <math>6</math> child tickets cost? |
− | <math>\textbf{(A) }35\qquad | + | <math>\textbf{(A) }$35\qquad |
− | \textbf{(B) }38.50\qquad | + | \textbf{(B) }$38.50\qquad |
− | \textbf{(C) }40\qquad | + | \textbf{(C) }$40\qquad |
− | \textbf{(D) }42\qquad | + | \textbf{(D) }$42\qquad |
− | \textbf{(E) }42.50</math> | + | \textbf{(E) }$42.50</math> |
[[2014 AMC 12A Problems/Problem 2|Solution]] | [[2014 AMC 12A Problems/Problem 2|Solution]] | ||
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Walking down Jane Street, Ralph passed four houses in a row, each painted a different color. He passed the orange house before the red house, and he passed the blue house before the yellow house. The blue house was not next to the yellow house. How many orderings of the colored houses are possible? | Walking down Jane Street, Ralph passed four houses in a row, each painted a different color. He passed the orange house before the red house, and he passed the blue house before the yellow house. The blue house was not next to the yellow house. How many orderings of the colored houses are possible? | ||
− | <math> \textbf{(A)}\ 2\qquad\textbf{(B)}\ 3\qquad\textbf{(C)}\ 4\qquad\textbf{(D) | + | <math> \textbf{(A)}\ 2\qquad\textbf{(B)}\ 3\qquad\textbf{(C)}\ 4\qquad\textbf{(D)}\ 5\qquad\textbf{(E)}\ 6</math> |
− | [[2014 AMC | + | [[2014 AMC 10A Problems/Problem 4|Solution]] |
==Problem 4== | ==Problem 4== | ||
Suppose that <math>a</math> cows give <math>b</math> gallons of milk in <math>c</math> days. At this rate, how many gallons of milk will <math>d</math> cows give in <math>e</math> days? | Suppose that <math>a</math> cows give <math>b</math> gallons of milk in <math>c</math> days. At this rate, how many gallons of milk will <math>d</math> cows give in <math>e</math> days? | ||
− | <math> \textbf{(A)}\ \frac{bde}{ac}\qquad\textbf{(B)}\ \frac{ac}{bde}\qquad\textbf{(C)}\ \frac{abde}{c}\qquad\textbf{(D) | + | <math> \textbf{(A)}\ \frac{bde}{ac}\qquad\textbf{(B)}\ \frac{ac}{bde}\qquad\textbf{(C)}\ \frac{abde}{c}\qquad\textbf{(D)}\ \frac{bcde}{a}\qquad\textbf{(E)}\ \frac{abc}{de}</math> |
− | [[2014 AMC | + | [[2014 AMC 10A Problems/Problem 6|Solution]] |
==Problem 5== | ==Problem 5== | ||
On an algebra quiz, <math>10\%</math> of the students scored <math>70</math> points, <math>35\%</math> scored <math>80</math> points, <math>30\%</math> scored <math>90</math> points, and the rest scored <math>100</math> points. What is the difference between the mean and median score of the students' scores on this quiz? | On an algebra quiz, <math>10\%</math> of the students scored <math>70</math> points, <math>35\%</math> scored <math>80</math> points, <math>30\%</math> scored <math>90</math> points, and the rest scored <math>100</math> points. What is the difference between the mean and median score of the students' scores on this quiz? | ||
− | <math> \textbf{(A)}\ 1\qquad\textbf{(B)}\ 2\qquad\textbf{(C)}\ 3\qquad\textbf{(D) | + | <math> \textbf{(A)}\ 1\qquad\textbf{(B)}\ 2\qquad\textbf{(C)}\ 3\qquad\textbf{(D)}\ 4\qquad\textbf{(E)}\ 5</math> |
− | [[2014 AMC | + | [[2014 AMC 10A Problems/Problem 5|Solution]] |
==Problem 6== | ==Problem 6== | ||
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A customer who intends to purchase an appliance has three coupons, only one of which may be used: | A customer who intends to purchase an appliance has three coupons, only one of which may be used: | ||
− | Coupon 1: <math>10\%</math> off the listed price if the listed price is at least <math>50</math> | + | Coupon 1: <math>10\%</math> off the listed price if the listed price is at least <math>$50</math> |
− | Coupon 2: <math>20</math> | + | Coupon 2: <math>$20</math> off the listed price if the listed price is at least <math>$100</math> |
− | Coupon 3: <math>18\%</math> off the amount by which the listed price exceeds <math>100</math> | + | Coupon 3: <math>18\%</math> off the amount by which the listed price exceeds <math>$100</math> |
For which of the following listed prices will coupon <math>1</math> offer a greater price reduction than either coupon <math>2</math> or coupon <math>3</math>? | For which of the following listed prices will coupon <math>1</math> offer a greater price reduction than either coupon <math>2</math> or coupon <math>3</math>? | ||
− | <math>\textbf{(A) }179.95\qquad | + | <math>\textbf{(A) }$179.95\qquad |
− | \textbf{(B) }199.95\qquad | + | \textbf{(B) }$199.95\qquad |
− | \textbf{(C) }219.95\qquad | + | \textbf{(C) }$219.95\qquad |
− | \textbf{(D) }239.95\qquad | + | \textbf{(D) }$239.95\qquad |
− | \textbf{(E) }259.95\qquad</math> | + | \textbf{(E) }$259.95\qquad</math> |
− | [[2014 AMC | + | [[2014 AMC 10A Problems/Problem 11|Solution]] |
==Problem 9== | ==Problem 9== | ||
Five positive consecutive integers starting with <math>a</math> have average <math>b</math>. What is the average of <math>5</math> consecutive integers that start with <math>b</math>? | Five positive consecutive integers starting with <math>a</math> have average <math>b</math>. What is the average of <math>5</math> consecutive integers that start with <math>b</math>? | ||
− | <math> \textbf{(A)}\ a+3\qquad\textbf{(B)}\ a+4\qquad\textbf{(C)}\ a+5\qquad\textbf{(D) | + | <math> \textbf{(A)}\ a+3\qquad\textbf{(B)}\ a+4\qquad\textbf{(C)}\ a+5\qquad\textbf{(D)}\ a+6\qquad\textbf{(E)}\ a+7</math> |
− | [[2014 AMC | + | [[2014 AMC 10A Problems/Problem 10|Solution]] |
==Problem 10== | ==Problem 10== | ||
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\textbf{(D) }245\qquad | \textbf{(D) }245\qquad | ||
\textbf{(E) }280\qquad</math> | \textbf{(E) }280\qquad</math> | ||
+ | |||
+ | [[2014 AMC 10A Problems/Problem 15|Solution]] | ||
==Problem 12== | ==Problem 12== | ||
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\textbf{(D) }2+\sqrt3\qquad | \textbf{(D) }2+\sqrt3\qquad | ||
\textbf{(E) }4\qquad</math> | \textbf{(E) }4\qquad</math> | ||
+ | |||
+ | [[2014 AMC 12A Problems/Problem 12|Solution]] | ||
==Problem 13== | ==Problem 13== | ||
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\textbf{(D) }3120\qquad | \textbf{(D) }3120\qquad | ||
\textbf{(E) }3125\qquad</math> | \textbf{(E) }3125\qquad</math> | ||
+ | |||
+ | [[2014 AMC 12A Problems/Problem 13|Solution]] | ||
==Problem 14== | ==Problem 14== | ||
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==Problem 15== | ==Problem 15== | ||
− | A five-digit palindrome is a positive integer with respective digits <math>abcba</math>, where <math>a</math> is non-zero. Let <math>S</math> be the sum of all five-digit palindromes. What is the sum of the digits of <math>S</math> | + | A five-digit palindrome is a positive integer with respective digits <math>abcba</math>, where <math>a</math> is non-zero. Let <math>S</math> be the sum of all five-digit palindromes. What is the sum of the digits of <math>S</math>? |
<math>\textbf{(A) }9\qquad | <math>\textbf{(A) }9\qquad | ||
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\textbf{(E) }999\qquad</math> | \textbf{(E) }999\qquad</math> | ||
− | [[2014 AMC | + | [[2014 AMC 10A Problems/Problem 20|Solution]] |
==Problem 17== | ==Problem 17== | ||
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<center><asy> | <center><asy> | ||
− | import | + | import graph3; |
import solids; | import solids; | ||
real h=2+2*sqrt(7); | real h=2+2*sqrt(7); | ||
currentprojection=orthographic((0.75,-5,h/2+1),target=(2,2,h/2)); | currentprojection=orthographic((0.75,-5,h/2+1),target=(2,2,h/2)); | ||
− | currentlight=light( | + | currentlight=light(4,-4,4); |
draw((0,0,0)--(4,0,0)--(4,4,0)--(0,4,0)--(0,0,0)^^(4,0,0)--(4,0,h)--(4,4,h)--(0,4,h)--(0,4,0)); | draw((0,0,0)--(4,0,0)--(4,4,0)--(0,4,0)--(0,0,0)^^(4,0,0)--(4,0,h)--(4,4,h)--(0,4,h)--(0,4,0)); | ||
− | draw(shift((1,3,1))*unitsphere, | + | draw(shift((1,3,1))*unitsphere,gray(0.85)); |
− | draw(shift((3,3,1))*unitsphere, | + | draw(shift((3,3,1))*unitsphere,gray(0.85)); |
− | draw(shift((3,1,1))*unitsphere, | + | draw(shift((3,1,1))*unitsphere,gray(0.85)); |
− | draw(shift((1,1,1))*unitsphere, | + | draw(shift((1,1,1))*unitsphere,gray(0.85)); |
− | draw(shift((2,2,h/2))*scale(2,2,2)*unitsphere, | + | draw(shift((2,2,h/2))*scale(2,2,2)*unitsphere,gray(0.85)); |
− | draw(shift((1,3,h-1))*unitsphere, | + | draw(shift((1,3,h-1))*unitsphere,gray(0.85)); |
− | draw(shift((3,3,h-1))*unitsphere, | + | draw(shift((3,3,h-1))*unitsphere,gray(0.85)); |
− | draw(shift((3,1,h-1))*unitsphere, | + | draw(shift((3,1,h-1))*unitsphere,gray(0.85)); |
− | draw(shift((1,1,h-1))*unitsphere, | + | draw(shift((1,1,h-1))*unitsphere,gray(0.85)); |
draw((0,0,0)--(0,0,h)--(4,0,h)^^(0,0,h)--(0,4,h)); | draw((0,0,0)--(0,0,h)--(4,0,h)^^(0,0,h)--(0,4,h)); | ||
</asy></center> | </asy></center> | ||
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\textbf{(E) }282\qquad</math> | \textbf{(E) }282\qquad</math> | ||
− | [[2014 AMC | + | [[2014 AMC 10A Problems/Problem 25|Solution]] |
==Problem 23== | ==Problem 23== | ||
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==Problem 25== | ==Problem 25== | ||
− | The parabola <math>P</math> has focus <math>(0,0)</math> and goes through the points <math>(4,3)</math> and <math>(-4,-3)</math>. For how many points <math>(x,y)\in P</math> with integer | + | The parabola <math>P</math> has focus <math>(0,0)</math> and goes through the points <math>(4,3)</math> and <math>(-4,-3)</math>. For how many points <math>(x,y)\in P</math> with integer coordinates is it true that <math>|4x+3y|\leq 1000</math>? |
<math>\textbf{(A) }38\qquad | <math>\textbf{(A) }38\qquad | ||
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[[2014 AMC 12A Problems/Problem 25|Solution]] | [[2014 AMC 12A Problems/Problem 25|Solution]] | ||
+ | |||
+ | ==See also== | ||
+ | |||
+ | {{AMC12 box|year=2014|ab=A|before=[[2013 AMC 12B Problems]]|after=[[2014 AMC 12B Problems]]}} | ||
+ | |||
+ | {{MAA Notice}} |
Latest revision as of 18:04, 11 April 2024
2014 AMC 12A (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
[hide]- 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
What is
Problem 2
At the theater children get in for half price. The price for adult tickets and child tickets is . How much would adult tickets and child tickets cost?
Problem 3
Walking down Jane Street, Ralph passed four houses in a row, each painted a different color. He passed the orange house before the red house, and he passed the blue house before the yellow house. The blue house was not next to the yellow house. How many orderings of the colored houses are possible?
Problem 4
Suppose that cows give gallons of milk in days. At this rate, how many gallons of milk will cows give in days?
Problem 5
On an algebra quiz, of the students scored points, scored points, scored points, and the rest scored points. What is the difference between the mean and median score of the students' scores on this quiz?
Problem 6
The difference between a two-digit number and the number obtained by reversing its digits is times the sum of the digits of either number. What is the sum of the two digit number and its reverse?
Problem 7
The first three terms of a geometric progression are , , and . What is the fourth term?
Problem 8
A customer who intends to purchase an appliance has three coupons, only one of which may be used:
Coupon 1: off the listed price if the listed price is at least
Coupon 2: off the listed price if the listed price is at least
Coupon 3: off the amount by which the listed price exceeds
For which of the following listed prices will coupon offer a greater price reduction than either coupon or coupon ?
Problem 9
Five positive consecutive integers starting with have average . What is the average of consecutive integers that start with ?
Problem 10
Three congruent isosceles triangles are constructed with their bases on the sides of an equilateral triangle of side length . The sum of the areas of the three isosceles triangles is the same as the area of the equilateral triangle. What is the length of one of the two congruent sides of one of the isosceles triangles?
Problem 11
David drives from his home to the airport to catch a flight. He drives miles in the first hour, but realizes that he will be hour late if he continues at this speed. He increases his speed by miles per hour for the rest of the way to the airport and arrives minutes early. How many miles is the airport from his home?
Problem 12
Two circles intersect at points and . The minor arcs measure on one circle and on the other circle. What is the ratio of the area of the larger circle to the area of the smaller circle?
Problem 13
A fancy bed and breakfast inn has rooms, each with a distinctive color-coded decor. One day friends arrive to spend the night. There are no other guests that night. The friends can room in any combination they wish, but with no more than friends per room. In how many ways can the innkeeper assign the guests to the rooms?
Problem 14
Let be three integers such that is an arithmetic progression and is a geometric progression. What is the smallest possible value of ?
Problem 15
A five-digit palindrome is a positive integer with respective digits , where is non-zero. Let be the sum of all five-digit palindromes. What is the sum of the digits of ?
Problem 16
The product , where the second factor has digits, is an integer whose digits have a sum of . What is ?
Problem 17
A rectangular box contains a sphere of radius and eight smaller spheres of radius . The smaller spheres are each tangent to three sides of the box, and the larger sphere is tangent to each of the smaller spheres. What is ?
Problem 18
The domain of the function is an interval of length , where and are relatively prime positive integers. What is ?
Problem 19
There are exactly distinct rational numbers such that and has at least one integer solution for . What is ?
Problem 20
In , , , and . Points and lie on and respectively. What is the minimum possible value of ?
Problem 21
For every real number , let denote the greatest integer not exceeding , and let The set of all numbers such that and is a union of disjoint intervals. What is the sum of the lengths of those intervals?
Problem 22
The number is between and . How many pairs of integers are there such that and
Problem 23
The fraction where is the length of the period of the repeating decimal expansion. What is the sum ?
Problem 24
Let , and for , let . For how many values of is ?
Problem 25
The parabola has focus and goes through the points and . For how many points with integer coordinates is it true that ?
See also
2014 AMC 12A (Problems • Answer Key • Resources) | |
Preceded by 2013 AMC 12B Problems |
Followed by 2014 AMC 12B 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.