Split 3, 12, 14, 26, and 91 into 2 groups of numbers such that the products of numbers in both groups are equal.

Find the sum of the numbers of the group that contains 14.

Split: Chia; Products: Tích; Equal: Bằng nhau; Sum: Tổng; Contains: Chứa.

(a)  

There are some $1 and $2 coins. The number of $1 coins is 2 times of that of $2 coins.

The total value of coins is $100. Find the number of $1 coins.

2 times: Hai lần; Total value: Tổng giá trị.

(a)  

John wrote a 3-digit number on a piece of paper and asked Peter to guess it.

Peter asked: “Is the number divisible by 21?”

John replied: “It is divisible by 21.”

Peter asked: “Is the number divisible by 9?”

John replied: “It is divisible by 9.”

Peter asked again: “Is it a square number?”

John said: “Yes, it is a square number.”

What is the number written by John?

3-digit number: Số có 3 chữ số; Divisible: Chia hết; Square number: Số chính phương.

(a)  

A class has 40 students. 26 students join the badminton class, 25 students join the judo class and 20 students join the dance class.

Each student joins at least one class.

Given that 23 students join two classes. How many students join all three classes?

At least: Ít nhất.

(a)  

Find the value of $$1+5+25+125+625+3125$$ .

Value: Giá trị.

(a)  

Find the value of $$2015^2-1015^2$$ .

(a)  

Find the value of $$1+1+2+3+5+8+...+144+233+377$$ .

(Remark: Starting from the third number, each number is the sum of the previous two numbers.)

Value: Giá trị.; Third number: Số thứ ba; Sum: Tổng; Previous: Phía trước.

(a)  

Find the value of $$\frac{2}{3}+\frac{2}{15}+\frac{2}{35}+...+\frac{2}{255}+\frac{2}{323}$$

Nếu đáp án là $$\frac{1}{2}$$ thì nhập là 1/2

(a)  

Convert $$0.\left(148\right)$$ into the simplest fraction.

Convert: Đổi; Simplest fraction: Phân số tối giản.

Nếu đáp án là $$\frac{1}{2}$$ thì nhập là 1/2

(a)  

Find the sum of all positive factors of 2015.

Sum: Tổng; Positive factors: Các ước.

(a)  

If a 5-digit number $$\overline{2015A}$$ is divisible by 8, find the value of A.

5-digit number: Số có 5 chữ số; Divisible: Chia hết; Value: Giá trị.

(a)  

Counting from 1 to 999, how many numbers are divisible by 6 or 9?

Counting: Đếm; Divisible: Chia hết

(a)  

When a 4-digit positive integer is divided by 5, 13, or 31 the remainders are all 2.

Find the least possible value of that positive integer.

4-digit positive integer: Số nguyên dương 4 chữ số; Divided by: Chia cho;

Remainder: Số dư; Least: Ít nhất; Value: Giá trị; Positive integer: Số nguyên dương.

(a)  

Find the smallest 3-digit number that can be divisible by 3 different prime numbers?

Smallest 3-digit number: Số nhỏ nhất có 3 chữ số; Divisible: Chia hết; Prime: Số nguyên tố.

(a)  

In the figure, the side length of the square is 7cm. Find the area of shaded region. ( . $$\pi=\frac{22}{7}$$ )

Figure: Hình vẽ; Side length: Độ dài cạnh; Square: Hình vuông;

Area: Diện tích; Shaded region: Phần tô đậm

(a)  

The side length of square ABCF is 18cm. Extend BC to D and connect AD. It is known that the area of triangle AEF is 90 $$cm^2$$ more than that of triangle DCE. Find the length of CD (in terms of cm). Side length: Chiều dài cạnh; Square: Hình vuông; Extend: Kéo dài; Connect: Nối; Area: Diện tích; Triangle: Tam giác; More than: Nhiều hơn; Length: Độ dài

(a)  

Rectangle ABCD is divided into 8 parts whose areas are shown below. Find the area of shaded region. Rectangle: Hình chữ nhật; Divied: Chia; Part: Phần; Area: Diện tích; Shaded region: Phần tô đậm.

(a)  

Paint a cube with edge length of 4cm with red colour.

If it is divided into small cubes with edge length of 1cm afterwards, find the numbers of small cubes with only 1 face is painted.

Cube: Khối lập phương; Edge: Cạnh; Length: Độ dài; Divided: Chia; Face: Một mặt.

(a)  

There is a cuboid. If its length is increased by 4cm, its volume is increased by 720 $$cm^3$$ ; if its width is decreased by 2cm, its volume is decreased by 264 $$cm^3$$ ; if its height is increased by 4cm, its volume is increased by 660 $$cm^3$$ .

Find the volume of the original cuboid.

Cuboid: Hình hộp chữ nhật; Length: Chiều dài; Increased: Tăng; Volume: Thể tích; Width: Chiều rộng; Decreased: Giảm đi; Height: Chiều cao; Original cuboid: Hình hộp chữ nhật ban đầu.

(a)  

Counting from 1 to 10000, how many numbers are there that have exactly two digits “5” and only one digit “4”?

Counting: Đếm; Exactly: Chính xác; Digit: Chữ số.

(a)  

How many 4-digit numbers are there whose product of all the digits is an odd number?

4-digit numbers: Số có 4 chữ số; Product: Tích; Digits: Chữ số; Odd: Lẻ

(a)  

There are 11 boys and 4 girls in a class. Choose 3 boys and 2 girls to form a study group.

How many ways are there in total?

Ways: Cách

(a)  

The attached figure is made up of 5 grids. A colour is filled into each box, and two adjacent grids do not share the same colour. If there are in total 4 colours to choose from to fill in the grids, how many ways are there to colour the figure?

Figure: Hình vẽ; Made up: Tạo bởi; Grids: Phần; Adjacent: Liền kề; Total: Tất cả; Ways: Cách.

(a)  

Arrange 5 letters A, B, C, D and E in a row. A and B must be adjacent. C and E must be adjacent. find the number of permutations.

Arrange: Sắp xếp; Letter: Chữ cái; Row: Hàng; Adjacent: Cạnh nhau; Permutations: Cách sắp xếp.

(a)