2015 AMC 8 Problems
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
Problem 1
How many square yards of carpet are required to cover a rectangular floor that is 
feet long and 
feet wide? (There are 3 feet in a yard.)
Problem 2
Point 
is the center of the regular octagon 
, and 
is the midpoint of the side 
What fraction of the area of the octagon is shaded?
![[asy] pair A,B,C,D,E,F,G,H,O,X; A=dir(45); B=dir(90); C=dir(135); D=dir(180); E=dir(-135); F=dir(-90); G=dir(-45); H=dir(0); O=(0,0); X=midpoint(A--B); fill(X--B--C--D--E--O--cycle,rgb(0.75,0.75,0.75)); draw(A--B--C--D--E--F--G--H--cycle); dot("$A$",A,dir(45)); dot("$B$",B,dir(90)); dot("$C$",C,dir(135)); dot("$D$",D,dir(180)); dot("$E$",E,dir(-135)); dot("$F$",F,dir(-90)); dot("$G$",G,dir(-45)); dot("$H$",H,dir(0)); dot("$X$",X,dir(135/2)); dot("$O$",O,dir(0)); draw(E--O--X); [/asy]](http://latex.artofproblemsolving.com/0/6/6/06635650c87a3cbd84380b9105fc49cc48e3792e.png)
Problem 3
Jack and Jill are going swimming at a pool that is one mile from their house. They leave home simultaneously. Jill rides her bicycle to the pool at a constant speed of 
miles per hour. Jack walks to the pool at a constant speed of 
miles per hour. How many minutes before Jack does Jill arrive?
Problem 4
The Centerville Middle School chess team consists of two boys and three girls. A photographer wants to take a picture of the team to appear in the local newspaper. She decides to have them sit in a row with a boy at each end and the three girls in the middle. How many such arrangements are possible?
Problem 5
Billy's basketball team scored the following points over the course of the first 11 games of the season: ![\[42, 47, 53, 53, 58, 58, 58, 61, 64, 65, 73\]](http://latex.artofproblemsolving.com/4/c/2/4c24d4c07e2a72cf04fa5c16f6d7ec90faad13b5.png)
If his team scores 40 in the 12th game, which of the following statistics will show an increase?
Problem 6
In 
, 
, and 
. What is the area of ?
Problem 7
Each of two boxes contains three chips numbered 
, 
, 
. A chip is drawn randomly from each box and the numbers on the two chips are multiplied. What is the probability that their product is even?
Problem 8
What is the smallest whole number larger than the perimeter of any triangle with a side of length 
and a side of length 
?
Problem 9
On her first day of work, Janabel sold one widget. On day two, she sold three widgets. On day three, she sold five widgets, and on each succeeding day, she sold two more widgets than she had sold on the previous day. How many widgets in total had Janabel sold after working 
days?
Problem 10
How many integers between 
and 
have four distinct digits?
Problem 11
In the small country of Mathland, all automobile license plates have four symbols. The first must be a vowel (A, E, I, O, or U), the second and third must be two different letters among the 21 non-vowels, and the fourth must be a digit (0 through 9). If the symbols are chosen at random subject to these conditions, what is the probability that the plate will read "AMC8"?
Problem 12
How many pairs of parallel edges, such as 
and 
or 
and 
, does a cube have?
![[asy] import three; currentprojection=orthographic(1/2,-1,1/2); /* three - currentprojection, orthographic */ draw((0,0,0)--(1,0,0)--(1,1,0)--(0,1,0)--cycle); draw((0,0,0)--(0,0,1)); draw((0,1,0)--(0,1,1)); draw((1,1,0)--(1,1,1)); draw((1,0,0)--(1,0,1)); draw((0,0,1)--(1,0,1)--(1,1,1)--(0,1,1)--cycle); label("$D$",(0,0,0),S); label("$A$",(0,0,1),N); label("$H$",(0,1,0),S); label("$E$",(0,1,1),N); label("$C$",(1,0,0),S); label("$B$",(1,0,1),N); label("$G$",(1,1,0),S); label("$F$",(1,1,1),N); [/asy]](http://latex.artofproblemsolving.com/4/4/0/4405a1743b5fd0c6b01eced58489bb15d61aac2f.png)
Problem 13
How many subsets of two elements can be removed from the set 
so that the mean (average) of the remaining numbers is 
?
Problem 14
Which of the following integers cannot be written as the sum of four consecutive odd integers?
Problem 15
At Euler Middle School, 
students voted on two issues in a school referendum with the following results: 
voted in favor of the first issue and 
voted in favor of the second issue. If there were exactly 
students who voted against both issues, how many students voted in favor of both issues?
Problem 16
In a middle-school mentoring program, a number of the sixth graders are paired with a ninth-grade student as a buddy. No ninth grader is assigned more than one sixth-grade buddy. If 
of all the ninth graders are paired with 
of all the sixth graders, what fraction of the total number of sixth and ninth graders have a buddy?
Problem 17
Jeremy's father drives him to school in rush hour traffic in minutes. One day there is no traffic, so his father can drive him 
miles per hour faster and gets him to school in minutes. How far in miles is it to school?
Problem 18
Problem 19
A triangle with vertices as 
, 
, and 
is plotted on a 
grid. What fraction of the grid is covered by the triangle?
[asy]
draw((1,0)--(1,5),linewidth(.5));
draw((2,0)--(2,5),linewidth(.5));
draw((3,0)--(3,5),linewidth(.5));
draw((4,0)--(4,5),linewidth(.5));
draw((5,0)--(5,5),linewidth(.5));
draw((6,0)--(6,5),linewidth(.5));
draw((0,1)--(6,1),linewidth(.5));
draw((0,2)--(6,2),linewidth(.5));
draw((0,3)--(6,3),linewidth(.5));
draw((0,4)--(6,4),linewidth(.5));
draw((0,5)--(6,5),linewidth(.5));
draw((0,0)--(0,6),EndArrow);
draw((0,0)--(7,0),EndArrow);
draw((1,3)--(4,4)--(5,1)--cycle);
label("
",(0,6),W); label("
",(7,0),S);
label("
",(1,3),dir(210)); label("
",(5,1),SE); label("
",(4,4),dir(100));
[/asy]
