Có 3 mặt lẻ là 1,3,5
3 mặt chẵn là 2,4,6
Nếu xắc 2 lần để ra tổng chẵn thì số xắc được trong 2 lần phải đồng tính chẵn lẻ
Nên số cách là 3*3*2=18 cách
1/ A dice of 6 faces is numbered 1,2,3,4,5 and 6. In how many ways will the sum be an even number if the dice is thrown twice? Solve this math in the shortest way.
(Bài này có trong đề thi Trần Đại Nghĩa đấy!! Chỉ có những người thông minh thật sự mới giải được!!!)
A software for a computer game was priced 20% above its cost price. It was later sold at 90% of its selling price and a profit of 360000 dong was made. Find the cost price of the software?Solve this math in the shortest and simplest way you know.
(Bài này khó lắm đấy, học giỏi lắm mới làm ra. Ai làm được thì mình like cho!!!)
các bạn giúp mình giải bài toán sau nhé !!!( math violympic đó ): A teacher has a bag of sweet for her students . If each student is given 4 sweet , the remaining number of sweet is 4 . If each student is given 5 sweet , the given will be short of 20 sweet . How many student are there in our class ?
Giúp mình giải nha mình cần giải xong vòng 6 trong ngày mai và ngày mai vì sắp chốt danh sách thi cấp trường rồi , ai giúp mình nhanh mình tặng 3 đúng nha
Fill in the blank with the suitable number
Question 1:
There are 49 students in a class. Boy students are the number of girl students. There are girl students in this class.
Question 2:
Calculate:
The value of A is
Question 3:
Calculate:
The value of A is
Question 4:
Jessica is 8 years old. Her grandmother is of her age. How old is Jessica's grandmother?
Answer: years old.
Question 5:
If the sum of denominator and numerator of a fraction is 52 and the denominator is 18 units more than the numerator then the numerator is
Question 6:
Find two consecutive even numbers if the first number is of the second number.
Answer: The second number is
Question 7:
Calculate:
The value of A is
Question 8:
How many natural numbers not greater than 1665 which are divisible by 5?
Answer: numbers
Question 9:
If then is
Question 10:
The sum of three consecutive even numbers is 960. The greatest numbers is
Combinatorics
21. 15 students join a competition. Only top 5 students can be promoted to next round. How many different way(s) of promotion advance is / are there?
Different way: Cách khác nhau.
22. It is known that there are 8 classes of grade 5 in a primary school. At least how many students are there in grade 5 to ensure there exist 41 students in the same class?
At least: Ít nhất; Ensure: Chắc chắn; Exist: Tồn tại.
23. Choose 3 digits from 1, 2, 3, 4, 6, 8 and 0 to form 3-digit numbers. How many even number(s) greater than 300 is / are there? (The repetition of digits is not allowed)
Digit: Chữ số; 3-digit number: Số có 3 chữ số; Even number: Số chẵn; Greater than: Lớn hơn; Repetition of digits is not allowed: Các chữ số không được lặp lại.
24. A flight of stairs has 10 steps. Peter can go up for 1 step, 2 steps or 3 steps each time. How many way(s) is / are there for Peter to go up the stairs?
Step: Bước; Way: Cách.
25. Numbers are drawn from 80 integers 20 to 99. At least how many number(s) is / are drawn at random to ensure that there are two numbers whose sum is 85?
Integer: Số nguyên; At least: Ít nhất; Random: Ngẫu nhiên; Ensure: Chắc chắn; Sum: Tổng.
~ End of Paper ~
Combinatorics
21. 15 students join a competition. Only top 5 students can be promoted to next round. How many different way(s) of promotion advance is / are there?
Different way: Cách khác nhau.
22. It is known that there are 8 classes of grade 5 in a primary school. At least how many students are there in grade 5 to ensure there exist 41 students in the same class?
At least: Ít nhất; Ensure: Chắc chắn; Exist: Tồn tại.
23. Choose 3 digits from 1, 2, 3, 4, 6, 8 and 0 to form 3-digit numbers. How many even number(s) greater than 300 is / are there? (The repetition of digits is not allowed)
Digit: Chữ số; 3-digit number: Số có 3 chữ số; Even number: Số chẵn; Greater than: Lớn hơn; Repetition of digits is not allowed: Các chữ số không được lặp lại.
24. A flight of stairs has 10 steps. Peter can go up for 1 step, 2 steps or 3 steps each time. How many way(s) is / are there for Peter to go up the stairs?
Step: Bước; Way: Cách.
25. Numbers are drawn from 80 integers 20 to 99. At least how many number(s) is / are drawn at random to ensure that there are two numbers whose sum is 85?
Integer: Số nguyên; At least: Ít nhất; Random: Ngẫu nhiên; Ensure: Chắc chắn; Sum: Tổng.
~ End of Paper ~
1: the perimeter of a circle is 15,7 dm. Its's area is...cm2
2: the ratio of the number of girls to the number of boys in a classroom is 5:4. When 10 girls left the classroom, the ratio of the number of boys to the number of girls became 4:3. How many students were in the classroom at first?
3: 47/250 dm3=...cm3
4: At the party 60% of the boys are dancing with 80% of the girls. How many people are dancing if there are 35 people ( A pair cludes only one boy and one girl)
5: An aquarium is 8dm deep, 12 dm long and 0,3 m wide. What is the volume of the aquarium in cubic centimeter?. Answer: the volume of the aquarium is...cm3
Fill in the blank with the suitable sign (>; =;<)
Question 1:
Compare: 3kg 50g 3500g
Question 2:
Compare: A = and B =
Answer: A B
Fill in the blank with the suitable number
Question 3:
Calculate:
(Write your answer in the simplest form)
Question 4:
Divide:
(Write your answer in the simplest form)
Question 5:
=
Question 6:
The sum of denominator and numerator of a fraction is 91 and the fraction is equal to . The denominator of the fraction is
Question 7:
The cost of eight spoons is 4 dollars. How much do 6 spoons cost?
Answer: 6 spoons cost dollars.
Question 8:
6km 32m = …m
The missing number is
Question 9:
In the following figure, ABED and BCFE are square. If the perimeter of the rectangle ACFD is 54cm then its area is
Question 10:
The sum of the page number of the last 3 pages of a book is 369. What is the last page number?
Answer: The last page number is
Bài 1: Joel is 8 years old. His mother is 34 years old. In how many years' time will his mother's age be three times Joel's age ?
Bài 2: The average of A and B is 20. The average of B and C is 15. The average of C and D is 18. Find the average of A and D ?
( Giải giúp mk với)
