TIMO Khối 8 – Vòng Quốc gia (Heat Round) – Đề số 2

Find the 3-digit number ACA . Given A and C are two non-zero digits and the 3-digit numbers formed by these two digits have the following properties: 1. CAC is divisible by 9; 2. CCA is divisible by 7; 3. ACC has an odd number of factors.

Chia hết;

Non-zero digits: Chữ số khác 0; 3-digit numbers: Số có 3 chữ số; Properties: Tính chất; Divisible:

Odd number of factors: Số ước lẻ

Split 7, 34, 51, 64, 69, 70, 92 and 720 into 2 groups of 4 numbers such that the products of numbers in both groups are equal. Find the sum of the numbers of the group that contains 7.

Split: Tách; Groups: Nhóm; Products: Tích; Equal: Bằng nhau; Sum: Tổng.

30 children, numbered 1 to 30, sit around a circle in order. Each child has an integer in hand. The child numbered 1 has the integer 1. The child numbered 2 has the integer 2. Given that the sum of the integers of any 21 consecutive children is equal to 7. What is the integer held by the child numbered 30?

Circle: Vòng tròn; Integer: Số nguyên; Sum: Tổng; Consecutive: Liên tiếp; Equal: Bằng.