Find a number, such that if that number is divided by 7, the remainder is 4. If that number is divided by 9, the remainder is 8 and the quotient is decreased by 2 units ?

They plant tree around a rectangle garden, the length is 61 m, the width is 25 m less than the length. They open two doors in the middle of the length ( like the picture ) ,each door wide 1 m. How many trees do they plant, such that trees are planted at regular intervals of 15dm and two side of door have different stake ? )

Find the irreducible fraction $\frac{a}{b}$such that if the numerator is increased by 6 and the denominator is increased by 21, the value of the new fraction is no change ?

( Write the result as a/b )

A rectangle has the area is 135 m². The length is  $\frac{3}{5}$ the width. Find the perimeter of the rectangle? ( m )

Find X such that : $\frac{1}{1}+\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+...+\frac{1}{X\times \left( X+1 \right):2}=\frac{3868}{1935}$ ?

Find $\overline{abc}$, such that that number  equals the sum of all natural consecutive number from 1 to $\overline{bc}$ ?

Find the natural number n , such that the sum of natural consecutive numbers from 1 to n is 190 ?

Thao ; Anh and Nam has 1403 marbles. Such that $\frac{2}{5}$ the number of  Anh’s marbles is 30 marbles more than $\frac{5}{8}$ the number of Thao’s marbles. And $\frac{5}{8}$the number of Thao’s marble is 7 marbles more than $\frac{1}{2}$ the number of Nam’s marbles . How many marbles does each person have ?

Two rectangles ABCD and AMNE have general part is square AMGD. Such that the area of ABCD is 120 $c{{m}^{2}}$larger than AMNE and the perimeter of ABCD is 20 cm larger than AMNE. Find the area of square AMGD ? ( cm²)

There are 4 different digits and different 0. Find the sum of all different 4 – digit numbers is written by those digits, such that the sum of the greatest and the smallest is 9889 ?

How many digits 0 are there in the consecutive sequence : 1 ; 2; 3; 4; …. ; 2013 ?

How many digits 5 are there in the consecutive sequence : 1 ; 2; 3; 4; …. ; 2013 ?

Find 3 – digit number is $\overline{abc}$, such that : $\frac{\overline{ab}}{\overline{c2}}=\frac{69}{92}$ ?

The sum of two numbers is 120. The first number is divided by the second number then we obtain a quotient is 4, a remainder of 5. Find the first number ?

Find a 2 – digit number, know that number is divided by the sum of digits, then its quotient by 6 and remainder of 2. If that number is divided by the product of digits, then its quotient by 5 and remainder of 2 ?