According to practical experience, for children who want to understand or add to the AMC8 American Mathematics Competition, it is one of the most scientific and effective ways to prepare for the AMC8 past questions. Even if you don't participate in the AMC8 competition and thoroughly understand the 600 past papers and the knowledge system behind them, then you will definitely learn mathematics very easily and easily in elementary and junior high school. (Of course, I personally recommend that children participate in the event that they have spare energy, and it is a very good practice to promote learning through competitions, which can stimulate children's competitiveness and enthusiasm for learning, and it is also a valuable experience and experience for children.) ）
In order to help children prepare for the exam more efficiently, I sorted out all the AMC8 real questions from 2000 to 2004 (the full version has a total of 600 questions, and corrected a small number of bugs in the original test paper), and exclusively produced a variety of ** exercises, using fragmented time, one year is enough to achieve good results in the 2025 AMC8 competition through self-study. See the end of this article for details.
The test point of this question is number theory (remainder), and the answer is c.
Let's say Isabella gets her first ice cream on week x, where x is 1-5 of the options. According to the title, the next 5 days she received the next 5 ice creams were x+10, x+20, x+30, x+40, x+50, we only need to divide these 5 numbers by 7 and the remainder is not 0 (the remainder is 0 is Sunday), that is, there is no multiple of 7. The classification is discussed as follows:
a.If x=1, then the next 5 digits are: 11, 21, 31, 4, 151, and the second is a multiple of 7 (i.e. the third ice cream falls on Sunday), which is incorrect.
b.If x=2, then the next 5 numbers are: 12, 22, 32, 42, 52, where 42 is a multiple of 7, false.
c.If x=3, then the next 5 numbers are: 13,23,33,43,53, and there is no multiple of 7, which is in line with the title.
d.If x=4, then the next 5 numbers are: 14, 24, 34, 44, 54, where 14 is a multiple of 7, false.
e.If x=5, then the next 5 numbers are: 15, 25, 35, 45, 55, where 35 is a multiple of 7, which is not true.
Let's expand it a little more and add x=6, then the next 5 numbers are: 16, 26, 36, 46, 56, where 56 is a multiple of 7, which is also incorrect.
To sum up, it can only be Wednesday, choose C.
Reminder: The questions on the day of the week are often remainder questions, and they are also common test question types, so you should carefully understand the idea of this question.
The test point of this question is number theory (remainder).
Suppose this 3-digit positive integer is n, and according to the title, n adds 4 to get n+4, then n+4 can be divisible by 11 at the same time. So n+4 is a multiple of the least common multiple of 6,9,11, and the least common multiple of 6,9,11 is 198. Suppose n=198k, so n=198k-4, and country n is a three-digit number, so 100 n=198k-4<1000, that is, 104 198k<5 and 14 198, the solution is k=1,2,3,4,5 a total of 5 numbers. So the answer is e.
The test focus for this question is arithmetic.
If the minimum number of coins is required, use large denominations whenever possible, i.e. 1 25 cents and 1 10 cents, for a total of 2 coins.
If you want to have the largest number of coins, use smaller denominations whenever possible, i.e. 7 5-cent coins.
Therefore, 7-2 = 5, choose e.
The test focus of this question is algebra (column equation solving application problem).
Assuming the book is x pages in total, then:
After the first day, Hui had 4x 5-12 pages left unread.
The next day, she still had (3 4)*(4x 5-12)-15=3x 5-24 pages unread.
After the third day, she still had (2 3)*)3x 5-24)-18=2x 5-34 pages unread, which equals 62 pages.
Therefore, 2x 5-34 = 62, 2x-170 = 310, 2x = 480, x = 240, choose c.
The test point of this question is arithmetic + algebra.
Note that the sum of the numbers in each row is the same as the sum of the numbers in each column (both are the sum of all the numbers in the matrix), so 40a = 75b, so a b = 75 40 = 15 8, so d is chosen.
The above-mentioned six-point growth exclusive production of ** practice questions, in line with learning and cognitive psychology, ** in the complete calendar year amc8 real questions, and will continue to update. AMC8 exam preparation is available, and repeated practice is also conducive to the improvement of mathematics ability in primary and junior high schools.
There are also supporting system learning documents and first-class materials as gifts. Welcome to understand.