1995 AMC 8 考试答案
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All of the real AMC 8, AMC 10, AMC 12, and AIME problems in our complete solution collection are used with official legal permission of the Mathematical Association of America (MAA).
1.
Walter has exactly one penny, one nickel, one dime and one quarter in his pocket. What percent of one dollar is in his pocket?
Difficulty rating: 370
Solution:
The coins total cents.
Since one dollar is cents, this is of a dollar.
Thus, the correct answer is D .
2.
Jose is years younger than Zack. Zack is years older than Inez. Inez is years old. How old is Jose?
Difficulty rating: 370
Solution:
Zack is years old.
Jose is years younger, so Jose is .
Thus, the correct answer is C .
3.
Which of the following operations has the same effect on a number as multiplying by and then dividing by
dividing by
dividing by
multiplying by
dividing by
multiplying by
Difficulty rating: 560
Solution:
Dividing by is the same as multiplying by so the two operations together multiply by
So the combined effect is multiplying by .
Thus, the correct answer is E .
4.
A teacher tells the class, "Think of a number, add to it, and double the result. Give the answer to your partner. Partner, subtract from the number you are given and double the result to get your answer." Ben thinks of and gives his answer to Sue. What should Sue's answer be?
Difficulty rating: 450
Solution:
Ben computes and gives to Sue.
Sue computes .
Thus, the correct answer is C .
5.
Find the smallest whole number that is larger than the sum
Difficulty rating: 660
Solution:
The whole-number parts sum to .
The fractions add to about which is between and So the total is between and and the smallest whole number larger than it is .
Thus, the correct answer is C .
6.
Figures and are squares. The perimeter of is and the perimeter of is The perimeter of is
Difficulty rating: 770
Solution:
Square has side and square has side
From the figure, the side of is so its perimeter is
Thus, the correct answer is C .
7.
At Clover View Junior High, one half of the students go home on the school bus. One fourth go home by automobile. One tenth go home on their bicycles. The rest walk home. What fractional part of the students walk home?
Difficulty rating: 730
Solution:
The students who ride make up
So the fraction who walk is
Thus, the correct answer is B .
8.
An American traveling in Italy wishes to exchange American money (dollars) for Italian money (lire). If lire how many lire will the traveler receive in exchange for
Difficulty rating: 820
Solution:
Since is of the traveler gets of lire.
That is lire.
Thus, the correct answer is D .
9.
Three congruent circles with centers and are tangent to the sides of rectangle as shown. The circle centered at has diameter and passes through points and The area of the rectangle is
Difficulty rating: 960
Solution:
Each circle has diameter The short side of the rectangle equals one diameter, so it is
Since the circle at passes through and all three circles have radius and the long side spans two full diameters: The area is
Thus, the correct answer is C .
10.
A jacket and a shirt originally sold for $80 and $40, respectively. During a sale Chris bought the $80 jacket at a discount and the $40 shirt at a discount. The total amount saved was what percent of the total of the original prices?
Difficulty rating: 930
Solution:
The jacket discount saves of and the shirt discount saves of The total saved is
The original total is so the percent saved is
Thus, the correct answer is A .
11.
Jane can walk any distance in half the time it takes Hector to walk the same distance. They set off in opposite directions around the outside of the -block area as shown. When they meet for the first time, they will be closest to
Difficulty rating: 1030
Solution:
The perimeter of the region is blocks, so when Jane and Hector meet they have together walked blocks. Since Jane walks twice as fast, she covers blocks and Hector covers
Starting from the middle of the bottom edge, Hector walks blocks (to then up to ), and Jane walks blocks (to up to then across the top to ). They meet at
Thus, the correct answer is D .
12.
A lucky year is one in which at least one date, when written in the form month/day/year, has the following property: the product of the month times the day equals the last two digits of the year. For example, is a lucky year because it has the date and Which of the following is NOT a lucky year?
13.
In the figure, and are right angles. If and then
Difficulty rating: 1150
Solution:
In triangle the angles at and are equal and so
Then In quadrilateral the angles at and are so
Thus, the correct answer is E .
14.
A team won of its first games. How many of the remaining games must this team win so it will have won exactly of its games for the season?
Difficulty rating: 930
Solution:
The season has games, and of is wins.
The team already has wins, so it needs more.
Thus, the correct answer is B .
15.
What is the th digit to the right of the decimal point in the decimal form of
Difficulty rating: 1060
Solution:
repeating with block length The digits in positions (multiples of ) are
Since is a multiple of the th digit is so the th digit starts the next block: it is
Thus, the correct answer is B .
16.
Students from three middle schools worked on a summer project. Seven students from Allen School worked for days. Four students from Balboa School worked for days. Five students from Carver School worked for days. The total amount paid for the students' work was $774. Assuming each student received the same amount for a day's work, how much did the students from Balboa School earn altogether?
$9.00
$48.38
$180.00
$193.50
$258.00
Difficulty rating: 1090
Solution:
The total student-days are
So each student-day pays Balboa worked student-days, earning
Thus, the correct answer is C .
17.
The table below gives the percent of students in each grade at Annville and Cleona elementary schools. The percentages for grades K, are: Annville: Cleona:
Annville has students and Cleona has students. In the two schools combined, what percent of the students are in grade
Difficulty rating: 980
Solution:
Annville has of sixth graders, and Cleona has of sixth graders.
Combined, that is out of students, which is
Thus, the correct answer is D .
18.
The area of each of the four congruent L-shaped regions of this -inch by -inch square is of the total area. How many inches long is the side of the center square?
Difficulty rating: 980
Solution:
The four L-shaped regions cover of the square, so the center square is the remaining of the total area.
The total area is square inches, so the center square has area and its side is inches.
Thus, the correct answer is C .
19.
The graph shows the distribution of the number of children in the families of the students in Ms. Jordan's English class. The median number of children in the family for this distribution is
Difficulty rating: 960
Solution:
The graph gives families with child, with with with and with for families.
The median is the th value in order. Listing the family sizes, the th value is
Thus, the correct answer is D .
20.
Diana and Apollo each roll a standard die obtaining a number at random from to What is the probability that Diana's number is larger than Apollo's number?
Difficulty rating: 1120
Solution:
There are equally likely outcomes, of which are ties, leaving outcomes with different numbers.
By symmetry, Diana is larger in exactly half of those, or so the probability is
Thus, the correct answer is B .
21.
A plastic snap-together cube has a protruding snap on one side and receptacle holes on the other five sides. What is the smallest number of these cubes that can be snapped together so that only receptacle holes are showing?
Difficulty rating: 1170
Solution:
Every cube's single snap must be plugged into another cube's hole to be hidden. With one, two, or three cubes, at least one snap is always left exposed.
Four cubes can be arranged in a square ring, each snap fitting into the neighbor's hole, so only receptacle holes show. The smallest number is
Thus, the correct answer is B .
22.
The number can be written as a product of a pair of positive two-digit numbers. What is the sum of this pair of numbers?
Difficulty rating: 1170
Solution:
The prime factorization is To split into two two-digit factors, pair the primes: and
These are the only two-digit pair, and their sum is
Thus, the correct answer is A .
23.
How many four-digit whole numbers are there such that the leftmost digit is odd, the second digit is even, and all four digits are different?
Difficulty rating: 1220
Solution:
The first digit is odd: choices. The second is even: choices (none of which repeats the odd first digit).
The third digit is any of the unused digits, and the fourth is any of the remaining. In total,
Thus, the correct answer is B .
24.
In parallelogram is the altitude to the base (with on ) and is the altitude to the base If and then
Difficulty rating: 1150
Solution:
Since we get In right triangle so
The area is and also So
Thus, the correct answer is C .
25.
Buses from Dallas to Houston leave every hour on the hour. Buses from Houston to Dallas leave every hour on the half hour. The trip from one city to the other takes hours. Assuming the buses travel on the same highway, how many Dallas-bound buses does a Houston-bound bus pass on the highway (not in the station)?
Difficulty rating: 1260
Solution:
Consider a bus leaving Dallas at arriving in Houston at It meets every Dallas-bound bus that is on the highway during that window.
Dallas-bound buses leave Houston on the half hour and take hours. The ones sharing the road (meeting away from a station) are those that left Houston at which is buses.
Thus, the correct answer is D .