Problem 1. Find two distinct numbers, given that their sum is three times their difference, and their product is eight times their difference.

Problem 2. The following sequence of numbers was written on a board: 1, 2, 3, 4, ..., 200. Uyen erased three consecutive numbers and the sum of the remaining numbers is 19848. Find the three numbers that were erased.

Problem 3. The price of a type of chalk in August dropped by 10% compared to that in June, but increased by 10% in October compared to that in August. How many percent has the price increased or decreased from June to October ?

Problem 4.Find the smallest whole number such that when it is multiplied by 12345679, the resulting product is a number having all of its digits equal to 8.

Problem5. Find the digits a and b such that the number  2016ab is divisible by 2 and 9, and has a remainder of 3 when divided by 5.

Find the missing number

Find the value of...

Find the 3rd number 

What is the smallest possible

Arrange the digits

There is one digit between the2's

In the figure

Find the total surface

Find the sum of...

 how many of them contain the shaded unit

find the area of...

Find the remainder

Between A and B,at least one was selected

Find the positions

Find the raitio...to ...

Find the length

Find an rrangement

John wrote a 3-digits number on a piece of a paper and asked Peter to guess it. Peter asked:"Is the number 173 ?".John replied:"One of the digits is correct, the position of that difiy is also correct". Peter asked again:"Is the number 123 ?". Two digits are correct, but the position of those digits are wrong." Peter asked again:"Is the number 324 ?". All three  are correct , but the digits are all in the wrong places." What is the number written by John ?

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