2018年AMC8考题和答案解析

1、2017 AMC 8 考题及答案Problem 1Which of the followi ng values is largest?伍声RJ + 1 + 7(B) 2 x 0 + 1 + 7(C)2 + 0 xl + 7(D) 2-p01x7(E) 2 x JYl x 7Problem 2Alicia, Bren da, and Colby were the can didates in a rece nt electio n forstude nt preside nt. The pie chart below shows how the votes weredistributed amo

2、ng the three can didates. If Brenda received 36 votes,the n how many votes were cast all together?(A) 70(B) 84(C) 100(D) 106(E) 120/wiki/index.php?title=2017_AMC_8_Problems/Proble m_2Problem 3What is the value of the expressi on(A) 4(B) 4a/2(C) 8(D) SV2 (E) 16When 0.000315 is multiplied by 7,928,564

3、 the product is closest to whichof the follow ing?(.A i 2 1 ：i (B) 2 l(：f(.1 i 2lij：j (.) 2KHI (E) 2 1()00/wiki/index.php?title=2017 AMC 8 Problems/Proble m 4Problem 5l*234*5-6-7*8What is the value of the expressi on?(A) 1020(B) 1120(C) 1220(D) 2240(E) 3360 HYPERLINK /wiki/i /wiki/i ndex.php?title=2

4、017_AMC_8_Problems/Proble m_5Problem 6If the degree measures of the angles of a triangle are in the ratio： ： ：； I,what is the degree measure of the largest an gle of the tria ngle?(A) 18(B) 36(C) 60(D) 72(E) 90http:/artofproblemsolvi /wiki/i ndex.php?title=2017_AMC_8_Problems/Proble m_6Problem 7Let

5、/be a 6-digit positive integer, such as 247247, whose first three digitsare the same as its last three digits taken in the same order. Which ofthe followi ng nu mbers must also be a factor of /?(A)ii (B)19(C)ioi (D)ill (E)nrqhttp:/artofproblemsolvi /wiki/i ndex.php?title=2017_AMC_8_Problems/Proble m

6、_7Problem 8Malcolm wants to visit Isabella after school today and knows the streetwhere she lives but does nt know her house nu mber. She tells him, Myhouse nu mber has two digits, and exactly three of the follow ing fourstateme nts about it are true.It is prime.It is eve n.It is divisible by 7.One

7、of its digits is 9.This information allows Malcolm to determine Isabellas house number.What is its units digit?(A) 4(B) 6(C) 7(D) 8(E) 9 HYPERLINK /wiki/i /wiki/i ndex.php?title=2017_AMC_8_Problems/Proble m_8Problem 9All of Marcys marbles are blue, red, green, or yellow. One third of hermarbles are

8、blue, one fourth of them are red, and six of them are gree n.What is the smallest nu mber of yellow marbles that Marcy could have?(A) 1(B) 2(C) 3(D) 4(E) 5 HYPERLINK /wiki/i /wiki/i ndex.php?title=2017_AMC_8_Problems/Proble m_9Problem 10A box contains five cards, nu mbered 1,2, 3, 4, and 5. Three ca

9、rds areselected ran domly without replaceme nt from the box. What is theprobability that 4 is the largest value selected?Problem 11A square-shaped floor is covered with con grue nt square tiles. If the totalnumber of tiles that lie on the two diagonals is 37, how many tiles coverthe floor?(A) 148(B)

10、 324(C) 361(D) 1296(E) 1369 HYPERLINK /wiki/i /wiki/i ndex.php?title=2017_AMC_8_Problems/Proble m 11Problem 12The smallest positive in teger greater tha n 1 that leaves a rema in der of 1whe n divided by 4, 5, and 6 lies betwee n which of the follow ing pairs ofnu mbers?(A) 2 aoid 19(B) 20 and 39(C)

11、 40 and 59(D) GO and 79(E) 80 and 124Problem 13Peter, Emma, and Kyler played chess with each other. Peter won 4 games and lost 2 games. Emma won 3 games and lost 3 games. If Kyler lost 3 games, how many games did he win?(A) U (B) 1(C) 2(D) 3(E) 4http:/artofproblemsolvi /wiki/i ndex.php?title=2017_AM

12、C_8_Problems/Proble m_13Problem 14Chloe and Zoe are both stude nts in Ms. Demea nors math class. Lastni ght they each solved half of the problems in their homeworkassig nmen t al one and the n solved the other half together. Chloe had correct an swers to only= of the problems she solved alone, butov

13、erall 汽九工 of her answers were correct. Zoe had correct answers to W 1 - of the problems she solved alone. What was Zoes overall perce ntage of correct an swers?(A)创 (B) 92(C)貂 (D) %(E)囲http:/artofproblemsolvi /wiki/i ndex.php?title=2017_AMC_8_Problems/Proble m_14Problem 15In the arrangement of lette

14、rs and numerals below, by how manydiffere nt paths can one spell AMC8? Beg inning at the A in the middle, a path allows only moves from one letter to an adjace nt (above, below,left, or right, but not diagonal) letter. One example of such a path is traced in the picture.88CC8MC8CMAMC8CMG88C8(A) 8(B)

15、 9(C) 12(D) 23(E) 36/wiki/index.php?title=2017 AMC 8 Problems/Proble m_15Problem 16In the figure below, choose pointDon 上-sothat 二m Dand 二丄丄Hhave equal perimeters. What is the areaof丄灯】？33125(A) -(B) -(C) 2(D) -(E)-Problem 17Start ing with some gold coins and some empty treasure chests, I tried to p

16、ut 9 gold coins in each treasure chest, but that left 2 treasure chests empty. So in stead I put 6 gold coins in each treasure chest, but the n I had 3 gold coins left over. How many gold coins did I have?(A) 9(B) 27(C) 45(D) 63(E) 81/wiki/index.php?title=2017 AMC 8 Problems/Proble m_17Problem 18In

17、the non-convex quadrilateral丄和二丄丿shown below, 丄M 丄is a rightan gle, .!/.；IP,/14, -J, an d.】/ ILWhat is the area of quadrilateral?(A) 12(B) 24(C) 26(D) 30(E) 36h卄 p:/wiki/index.php?title=2017_AMC_8_Problems/Proble m_18Problem 19For any positive integer /, the notationl / denotes the product of theint

18、egers I through f. What is the largest integer -for which ； is a factor ofthe sum屮工(A) 23(B) 24(C) 25(D) 26(E) 27An integer betweenI n(H andinclusive, is chosen at random. Whatis the probability that it is an odd integer whose digits are all distinct?Problem 21Suppose and care non zero real nu mbers

19、, an d心丨 丨厂 ：).Whatare the possible value(s) fora b c abc111a|&!|c|g&c|?(A) 0(B) 1 and - 1(C) 2 and 2(D)2： and 2http:/artofproblemsolvi /wiki/i ndex.php?title=2017_AMC_8_Problems/Proble m 21Problem 22In the right triangle丄,衣 】2丄江一，and angle is a right angle.A semicircle is in scribed in the tria ngl

20、e as show n. What is the radius ofthe semicircle?T1359IU6U叫 5C)）3 HYPERLINK /wiki/i /wiki/i ndex.php?title=2017_AMC_8_Problems/Proble m_22Problem 23Each day for four days, Linda traveled for one hour at a speed thatresulted in her traveling one mile in an integer number of minutes. Eachday after the

21、 first, her speed decreased so that the nu mber of minu testo travel one mile in creased by 5 minu tes over the preced ing day. Eachof the four days, her dista nee traveled was also an in teger nu mber ofmiles. What was the total nu mber of miles for the four trips?(A) 10(B) 15(C) 25(D) 50(E) 82| HYPERLINK /wiki/i /wiki/i ndex.php?title=2017_AMC_8_Problems/Proble m_23Problem 24Mrs. San ders h