Difference between revisions of "2014 AMC 8 Problems"
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+ | {{AMC8 Problems|year=2014|}} | ||
==Problem 1== | ==Problem 1== | ||
+ | Harry and Terry are each told to calculate <math>8-(2+5)</math>. Harry gets the correct answer. Terry ignores the parentheses and calculates <math>8-2+5</math>. If Harry's answer is <math>H</math> and Terry's answer is <math>T</math>, what is <math>H-T</math>? | ||
− | |||
− | <math> \textbf{(A) }-10\qquad\textbf{(B) }-6\qquad\textbf{(C) }0\qquad\textbf{(D) }6\qquad\textbf{(E) }10 </math> | + | <math>\textbf{(A) }-10\qquad\textbf{(B) }-6\qquad\textbf{(C) }0\qquad\textbf{(D) }6\qquad \textbf{(E) }10</math> |
[[2014 AMC 8 Problems/Problem 1|Solution]] | [[2014 AMC 8 Problems/Problem 1|Solution]] | ||
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==Problem 5== | ==Problem 5== | ||
− | Margie's car can go 32 miles on a gallon of gas, and gas currently costs | + | Margie's car can go 32 miles on a gallon of gas, and gas currently costs $4 per gallon. How many miles can Margie drive on $20? |
<math> \textbf{(A) }64\qquad\textbf{(B) }128\qquad\textbf{(C) }160\qquad\textbf{(D) }320\qquad\textbf{(E) }640 </math> | <math> \textbf{(A) }64\qquad\textbf{(B) }128\qquad\textbf{(C) }160\qquad\textbf{(D) }320\qquad\textbf{(E) }640 </math> | ||
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==Problem 8== | ==Problem 8== | ||
− | Eleven members of the Middle School Math Club each paid the same amount for a guest speaker to talk about problem solving at their math club meeting. | + | Eleven members of the Middle School Math Club each paid the same integer amount for a guest speaker to talk about problem solving at their math club meeting. In all, they paid their guest speaker <math>\textdollar\underline{1}\underline{A}\underline{2} </math>. What is the missing digit A of this 3-digit number? |
<math> \textbf{(A) }0\qquad\textbf{(B) }1\qquad\textbf{(C) }2\qquad\textbf{(D) }3\qquad\textbf{(E) }4 </math> | <math> \textbf{(A) }0\qquad\textbf{(B) }1\qquad\textbf{(C) }2\qquad\textbf{(D) }3\qquad\textbf{(E) }4 </math> | ||
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==Problem 12== | ==Problem 12== | ||
− | A magazine printed photos of three celebrities along with three photos of the celebrities as babies. The baby pictures did not identify the celebrities. | + | A magazine printed photos of three celebrities along with three photos of the celebrities as babies. The baby pictures did not identify the celebrities. Readers were asked to match each celebrity with the correct baby pictures. What is the probability that a reader guessing at random will match all three correctly as a fraction? |
<math> \textbf{(A) }\frac{1}{9}\qquad\textbf{(B) }\frac{1}{6}\qquad\textbf{(C) }\frac{1}{4}\qquad\textbf{(D) }\frac{1}{3}\qquad\textbf{(E) }\frac{1}{2} </math> | <math> \textbf{(A) }\frac{1}{9}\qquad\textbf{(B) }\frac{1}{6}\qquad\textbf{(C) }\frac{1}{4}\qquad\textbf{(D) }\frac{1}{3}\qquad\textbf{(E) }\frac{1}{2} </math> | ||
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If <math>n</math> and <math>m</math> are integers and <math>n^2+m^2</math> is even, which of the following is impossible? | If <math>n</math> and <math>m</math> are integers and <math>n^2+m^2</math> is even, which of the following is impossible? | ||
− | <math>\textbf{(A) }n</math> and <math>m</math> are even <math>\qquad\textbf{(B) }n</math> and <math>m</math> are odd <math>\qquad\textbf{(C) }n+m</math> is even <math>\qquad\textbf{(D) }n+m</math> is odd <math>\qquad \textbf{(E) }</math> none of these are impossible | + | <math>\textbf{(A) }n</math> and <math>m</math> are even <math>\qquad\textbf{(B) }n</math> and <math>m</math> are odd <math>\qquad\textbf{(C) } n+m</math> is even <math>\qquad\textbf{(D) } |
+ | n+m</math> is odd <math>\qquad \textbf{(E) }</math> none of these are impossible | ||
[[2014 AMC 8 Problems/Problem 13|Solution]] | [[2014 AMC 8 Problems/Problem 13|Solution]] | ||
==Problem 14== | ==Problem 14== | ||
− | Rectangle ABCD and right triangle DCE have the same area. They are joined to form a trapezoid, as shown. What is DE? | + | Rectangle <math>ABCD</math> and right triangle <math>DCE</math> have the same area. They are joined to form a trapezoid, as shown. What is <math>DE</math>? |
<asy> | <asy> | ||
size(250); | size(250); | ||
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label("$E$",E,S); | label("$E$",E,S); | ||
label("$5$",A/2,W); | label("$5$",A/2,W); | ||
− | label("$6$",(A+D)/2,N);</asy> | + | label("$6$",(A+D)/2,N); |
+ | </asy> | ||
<math> \textbf{(A) }12\qquad\textbf{(B) }13\qquad\textbf{(C) }14\qquad\textbf{(D) }15\qquad\textbf{(E) }16 </math> | <math> \textbf{(A) }12\qquad\textbf{(B) }13\qquad\textbf{(C) }14\qquad\textbf{(D) }15\qquad\textbf{(E) }16 </math> | ||
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Four children were born at City Hospital yesterday. Assume each child is equally likely to be a boy or a girl. Which of the following outcomes is most likely? | Four children were born at City Hospital yesterday. Assume each child is equally likely to be a boy or a girl. Which of the following outcomes is most likely? | ||
− | <math> \textbf{(A) }</math> | + | <math>\textbf{(A) } </math> All 4 are boys <math>\textbf{(B) } </math> All 4 are girls <math>\textbf{(C) } </math> 2 are girls and 2 are boys |
+ | <math>\textbf{(D) } </math> 3 are of one gender and 1 is of the other gender <math>\textbf{(E) } </math> All of these outcomes are equally likely | ||
[[2014 AMC 8 Problems/Problem 18|Solution]] | [[2014 AMC 8 Problems/Problem 18|Solution]] | ||
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==Problem 20== | ==Problem 20== | ||
− | Rectangle ABCD has sides CD=3 and DA=5. A circle of | + | Rectangle <math>ABCD</math> has sides <math>CD=3</math> and <math>DA=5</math>. A circle with a radius of <math>1</math> is centered at <math>A</math>, a circle with a radius of <math>2</math> is centered at <math>B</math>, and a circle with a radius of <math>3</math> is centered at <math>C</math>. Which of the following is closest to the area of the region inside the rectangle but outside all three circles? |
<asy> | <asy> | ||
draw((0,0)--(5,0)--(5,3)--(0,3)--(0,0)); | draw((0,0)--(5,0)--(5,3)--(0,3)--(0,0)); | ||
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==Problem 23== | ==Problem 23== | ||
Three members of the Euclid Middle School girls' softball team had the following conversation. | Three members of the Euclid Middle School girls' softball team had the following conversation. | ||
+ | |||
Ashley: I just realized that our uniform numbers are all 2-digit primes. | Ashley: I just realized that our uniform numbers are all 2-digit primes. | ||
+ | |||
Bethany: And the sum of your two uniform numbers is the date of my birthday earlier this month. | Bethany: And the sum of your two uniform numbers is the date of my birthday earlier this month. | ||
+ | |||
Caitlin: That's funny. The sum of your two uniform numbers is the date of my birthday later this month. | Caitlin: That's funny. The sum of your two uniform numbers is the date of my birthday later this month. | ||
− | Ashley: And the sum of | + | |
+ | Ashley: And the sum of your two uniform numbers is today's date. | ||
What number does Caitlin wear? | What number does Caitlin wear? | ||
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==Problem 24== | ==Problem 24== | ||
− | One day the Beverage Barn sold 252 cans of soda to 100 customers, and every customer | + | One day the Beverage Barn sold 252 cans of soda to 100 customers, and every customer bought at least one can of soda. What is the maximum possible median number of cans of soda bought per customer on that day? |
− | <math> \textbf{(A) }2.5\qquad\textbf{(B) }3.0\qquad\textbf{(C) }3.5\qquad\textbf{(D) }4.0\qquad\textbf{(E) }4.5 </math> | + | <math>\textbf{(A) }2.5\qquad\textbf{(B) }3.0\qquad\textbf{(C) }3.5\qquad\textbf{(D) }4.0\qquad\textbf{(E) }4.5 </math> |
[[2014 AMC 8 Problems/Problem 24|Solution]] | [[2014 AMC 8 Problems/Problem 24|Solution]] | ||
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A straight one-mile stretch of highway, 40 feet wide, is closed. Robert rides his bike on a path composed of semicircles as shown. If he rides at 5 miles per hour, how many hours will it take to cover the one-mile stretch? | A straight one-mile stretch of highway, 40 feet wide, is closed. Robert rides his bike on a path composed of semicircles as shown. If he rides at 5 miles per hour, how many hours will it take to cover the one-mile stretch? | ||
− | |||
<asy> | <asy> | ||
size(10cm); pathpen=black; pointpen=black; | size(10cm); pathpen=black; pointpen=black; | ||
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D(arc((4,0),1,0,180)); | D(arc((4,0),1,0,180)); | ||
D(arc((6,0),1,180,240)); | D(arc((6,0),1,180,240)); | ||
− | |||
− | |||
D((-1.5,-1)--(5.5,-1));</asy> | D((-1.5,-1)--(5.5,-1));</asy> | ||
+ | Note: 1 mile = 5280 feet | ||
<math> \textbf{(A) }\frac{\pi}{11}\qquad\textbf{(B) }\frac{\pi}{10}\qquad\textbf{(C) }\frac{\pi}{5}\qquad\textbf{(D) }\frac{2\pi}{5}\qquad\textbf{(E) }\frac{2\pi}{3} </math> | <math> \textbf{(A) }\frac{\pi}{11}\qquad\textbf{(B) }\frac{\pi}{10}\qquad\textbf{(C) }\frac{\pi}{5}\qquad\textbf{(D) }\frac{2\pi}{5}\qquad\textbf{(E) }\frac{2\pi}{3} </math> | ||
[[2014 AMC 8 Problems/Problem 25|Solution]] | [[2014 AMC 8 Problems/Problem 25|Solution]] | ||
+ | |||
+ | ==See Also== | ||
+ | {{AMC8 box|year=2014|before=[[2013 AMC 8 Problems|2013 AMC 8]]|after=[[2015 AMC 8 Problems|2015 AMC 8]]}} | ||
+ | * [[AMC 8]] | ||
+ | * [[AMC 8 Problems and Solutions]] | ||
+ | * [[Mathematics competition resources|Mathematics Competition Resources]] |
Latest revision as of 11:08, 13 January 2024
2014 AMC 8 (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
Harry and Terry are each told to calculate . Harry gets the correct answer. Terry ignores the parentheses and calculates . If Harry's answer is and Terry's answer is , what is ?
Problem 2
Paul owes Paula 35 cents and has a pocket full of 5-cent coins, 10-cent coins, and 25-cent coins that he can use to pay her. What is the difference between the largest and the smallest number of coins he can use to pay her?
Problem 3
Isabella had a week to read a book for a school assignment. She read an average of 36 pages per day for the first three days and an average of 44 pages per day for the next three days. She then finished the book by reading 10 pages on the last day. How many pages were in the book?
Problem 4
The sum of two prime numbers is 85. What is the product of these two prime numbers?
Problem 5
Margie's car can go 32 miles on a gallon of gas, and gas currently costs $4 per gallon. How many miles can Margie drive on $20?
Problem 6
Six rectangles each with a common base width of 2 have lengths of 1, 4, 9, 16, 25, and 36. What is the sum of the areas of the six rectangles?
Problem 7
There are four more girls than boys in Ms. Raub's class of 28 students. What is the ratio of number of girls to the number of boys in her class?
Problem 8
Eleven members of the Middle School Math Club each paid the same integer amount for a guest speaker to talk about problem solving at their math club meeting. In all, they paid their guest speaker . What is the missing digit A of this 3-digit number?
Problem 9
In , is a point on side such that and measures . What is the degree measure of ?
Problem 10
The first AMC 8 was given in 1985 and it has been given annually since that time. Samantha turned 12 years old the year that she took the seventh AMC 8. In what year was Samantha born?
Problem 11
Jack wants to bike from his house to Jill's house, which is located three blocks east and two blocks north of Jack's house. After biking each block, Jack can continue either east or north, but he needs to avoid a dangerous intersection one block east and one block north of his house. In how many ways can he reach Jill's house by biking a total of five blocks?
Problem 12
A magazine printed photos of three celebrities along with three photos of the celebrities as babies. The baby pictures did not identify the celebrities. Readers were asked to match each celebrity with the correct baby pictures. What is the probability that a reader guessing at random will match all three correctly as a fraction?
Problem 13
If and are integers and is even, which of the following is impossible?
and are even and are odd is even is odd none of these are impossible
Problem 14
Rectangle and right triangle have the same area. They are joined to form a trapezoid, as shown. What is ?
Problem 15
The circumference of the circle with center is divided into 12 equal arcs, marked the letters through as seen below. What is the number of degrees in the sum of the angles and ?
Problem 16
The "Middle School Eight" basketball conference has 8 teams. Every season, each team plays every other conference team twice (home and away), and each team also plays 4 games against non-conference opponents. What is the total number of games in a season involving the "Middle School Eight" teams?
Problem 17
George walks mile to school. He leaves home at the same time each day, walks at a steady speed of miles per hour, and arrives just as school begins. Today he was distracted by the pleasant weather and walked the first mile at a speed of only miles per hour. At how many miles per hour must George run the last mile in order to arrive just as school begins today?
Problem 18
Four children were born at City Hospital yesterday. Assume each child is equally likely to be a boy or a girl. Which of the following outcomes is most likely?
All 4 are boys All 4 are girls 2 are girls and 2 are boys 3 are of one gender and 1 is of the other gender All of these outcomes are equally likely
Problem 19
A cube with 3-inch edges is to be constructed from 27 smaller cubes with 1-inch edges. Twenty-one of the cubes are colored red and 6 are colored white. If the 3-inch cube is constructed to have the smallest possible white surface area showing, what fraction of the surface area is white?
Problem 20
Rectangle has sides and . A circle with a radius of is centered at , a circle with a radius of is centered at , and a circle with a radius of is centered at . Which of the following is closest to the area of the region inside the rectangle but outside all three circles?
Problem 21
The 7-digit numbers and are each multiples of 3. Which of the following could be the value of ?
Problem 22
A 2-digit number is such that the product of the digits plus the sum of the digits is equal to the number. What is the units digit of the number?
Problem 23
Three members of the Euclid Middle School girls' softball team had the following conversation.
Ashley: I just realized that our uniform numbers are all 2-digit primes.
Bethany: And the sum of your two uniform numbers is the date of my birthday earlier this month.
Caitlin: That's funny. The sum of your two uniform numbers is the date of my birthday later this month.
Ashley: And the sum of your two uniform numbers is today's date.
What number does Caitlin wear?
Problem 24
One day the Beverage Barn sold 252 cans of soda to 100 customers, and every customer bought at least one can of soda. What is the maximum possible median number of cans of soda bought per customer on that day?
Problem 25
A straight one-mile stretch of highway, 40 feet wide, is closed. Robert rides his bike on a path composed of semicircles as shown. If he rides at 5 miles per hour, how many hours will it take to cover the one-mile stretch?
Note: 1 mile = 5280 feet
See Also
2014 AMC 8 (Problems • Answer Key • Resources) | ||
Preceded by 2013 AMC 8 |
Followed by 2015 AMC 8 | |
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 AJHSME/AMC 8 Problems and Solutions |