TRUNG TÂM TOÁN SONG NGỮ HOA KỲ - LỚP CÔ THÚY- ZALO 0986692706 AMO OFFICIAL TEST 2015 – GRADE ĐỀ THI CHÍNH THỨC AMO NĂM 2015 - LỚP INSTRUCTION CHỈ DẪN Please DO NOT OPEN the contest booklet until the Proctor has given permission TIME: hour 30 minutes Attempt all 25 questions Each question scores point No points are deducted for incorrect answers Write your answers neatly in the answer sheet in the booklet PROCTORING: No one may help any student in any way during the contest No calculators are allowed All students must fill in your Name, Class and School MINIMUM TIME: Students must stay in the exam hall at least lh 15 sheet Students must show detailed working and put answers in the answer No spare papers can be used in writing this contest Enough space is provided for your working of each question TRUNG TÂM TOÁN SONG NGỮ HOA KỲ - LỚP CÔ THÚY- ZALO 0986692706 Question What number can replace the square to make the statement true? 11+ 12+ 13 +14 + 15 + 16 = x O ĐA: ( 11 +16 ) + ( 12 + 15 ) + ( 13 +14 ) = 27 + 27 + 27 = x 27= x O x 27= x O O = 27 Question The figure shown at the right is made by placing cubes on top of each other with no gaps Not all cubes are visible How many cubes does the figure contain? ĐA: 16 Question Amy chooses any number from 13 to 37 She adds 68 to it and subtracts 37 from the resulting sum Afterwards she adds 19 to the difference Finally, she subtracts original number from the sum What is the number she will get after all these operations? ĐA: Amy chọn số từ 13 đến 37 Cô cộng 68; trừ 37 , cộng 19 , trừ số ban đầu Hỏi sau tất phép tính kết số nào? A + 68 – 37 + 19 – A = ( A – A ) + 68 – 37 + 19 = 31 + 19 = 50 Question Tom is older than Jerry but younger than Ben Leonardo is older than Christopher but younger than Tom Who is the eldest of these five people? ĐA: Tom nhiều tuổi Jerry Ben Leo nhiều tuổi Chris tuổi Tom Hỏi nhiều tuổi nhất? B> T>J T> L>C Vậy Ben nhiều tuổi Question Pablo has nickels and dimes and no other coins He has five more dimes than nickels Altogether, he has $1.40 How many nickels does Pablo have? (Note: Nickel is a coin worth of cents; Dime is a coin worth of 10 cents) ĐA: TRUNG TÂM TOÁN SONG NGỮ HOA KỲ - LỚP CÔ THÚY- ZALO 0986692706 Pablo có đồng nickel đồng dime khơng có đồng khác Anh số đồng dime nhiều nickel đồng Tổng cộng, anh có 140 Hỏi anh có đồng nickel? nickel = cents dime = 10 cents đô = 100 cents Cách 1: Số nickel =6 Số dime = 11 Nickel x 5 x5 Dime x 10 10 11 x10 12 Tổng 65 80 95 110 125 140 Cách 2: Question Find the sum of 102 + 203+304 + 405 +506 + 607 +708 + 809 + 901 ĐA: 4545 Đơn vị : tổng = 45 viết nhớ Hàng chục : tổng = nhớ viết Hàng trăm : tổng = 45 viết 45 4545 Question The number has exactly four unique factors: 1, 2, 3, and How many whole numbers less than 10 have an odd number of unique factors? ĐA: Ước số mà số chia hết cho Ư ( 6) = { ; ; ; 6} Ước có số ( chẵn ) Ư ( ) = { ; ; 4} Ước có số ( lẻ ) TRUNG TÂM TOÁN SONG NGỮ HOA KỲ - LỚP CÔ THÚY- ZALO 0986692706 Ư ( ) = { } có ước ( lẻ ) Ư ( ) = { ; } ước ( chẵn ) = x1 4=2x2=1x4 9=3x3=1x9 Những số viết dạng a x a có số lẻ ước Vậy số có số lẻ ước nhỏ 10 là: ; ; có số VD: The number has exactly four unique factors: 1, 2, 3, and How many whole numbers less than 30 have an odd number of unique factors? 16 25 Có số Question In each box, the three numbers on the top row are used to obtain the number in the bottom row If the same pattern is used in each box, what is the value of N? ĐA: Quy luật : 11 = x + N = x + = 17 Question Pascal's Triangle is shown here, The first and last number in each row is Each of the other numbers is the sum of the two numbers diagonally above it, as shown by the arrows Five rows are shown If the pattern is continued for two more rows, what is the sum of all seven numbers in that row? ĐA: Hàng 1: tổng = TRUNG TÂM TOÁN SONG NGỮ HOA KỲ - LỚP CÔ THÚY- ZALO 0986692706 Hàng 2: tổng = Hàng 3: tổng = Hàng 4: tổng = Hàng 5: tổng = 16 Quy luật : 1; 2; 4; 8; 16 nhân Hàng tổng= 16 x = 32 Hàng có tổng : 32 x = 64 Question 10 Stacy has three children: Amy, Ben and Carl They are 3,5 and 13 years old When 31 is divided by Carl's age, the remainder is Ben is younger than Carl Who is oldest among the children? ĐA: Amy ; Ben ; Carl - ; ; 13 31 chia Carl dư B