Compare:

$\frac{1995}{1996}$ và $\frac{1996}{1997}$

Find a fraction knowing that move 5 units in the denominator up the numerator we get a new fraction equals 1, if move 9 units in the numerator down the denominator we get a new fraction equals $\frac{3}{5}$  ?

Find a fraction knowing that move 5 units in the denominator up the numerator we get a new fraction equals 1, if move 5 units in the numerator down the denominator we get a new fraction equals $\frac{4}{5}$ ?

Find a fraction. Knowing that move 8 units in the denominator up the numerator we get a fraction equals 1. If move 5 units in the denominator up the numerator we have a fraction is $\frac{4}{5}$ ?

Find a fraction knowing that fraction equals $\frac{2}{5}$  and the numerator increased by 45 units, we get a new fraction equals $\frac{13}{20}$ ?

The fraction equals $\frac{5}{8}$ . If the numerator increased by 6 units, we get a new fraction equal $\frac{2}{3}$ . Find that fraction ?

Find a fraction knowing that the numerator increased by 10 units we have a new fraction $\frac{5}{4}$ , If  the numerator decreased by 8 unit to get the fraction $\frac{4}{5}$ ?

The fraction $\frac{17}{25}$ . How many units did we decreased in the numerator and the denominator to get new fraction, simplifying new fraction we have fraction $\frac{2}{3}$ ?

Find the fraction $\frac{a}{b}$  with a + b = 96. If simplifying fraction $\frac{a}{b}$ we have the fraction $\frac{1}{3}$ . Find the fraction $\frac{a}{b}$ ?

The fraction $\frac{a}{b}$ with a + b = 200, If simplifying $\frac{a}{b}$ we have fraction $\frac{3}{5}$ . Find the fraction $\frac{a}{b}$?

The fraction $\frac{54}{63}$. Find the natural number a so that the numerator decreased by a and the denominator increased by a of the fraction we have a new fracion with value is $\frac{4}{5}$?

Calculate:

$\frac{3}{2\text{x}5}+\frac{3}{5\text{x}8}+\frac{3}{8\text{x}11}+....+\frac{3}{101\text{x}104}$

( Write the result as a/b )

Calculate:

$2-\left( \frac{4}{1\text{x}5}+\frac{4}{5\text{x}9}+\frac{4}{9\text{x}13}+\frac{4}{13\text{x}17}+\frac{4}{17\text{x}21} \right)$

( Write the result as a/b )

Calculate:

 $\frac{1}{1\text{x}3}+\frac{1}{3\text{x}5}+\frac{1}{5\text{x}7}+\frac{1}{7\text{x}9}+\frac{1}{9\text{x}11}$

( Write the result as a/b )

Calculate:

$\frac{1}{1\text{x}3}+\frac{1}{3\text{x}5}+\frac{1}{5\text{x}7}+....+\frac{1}{99\text{x}101}$

( Write the result as a/b )

Calculate:

 $\frac{1}{1\text{x4}}+\frac{1}{\text{4x7}}+\frac{1}{\text{7x10}}+\frac{1}{\text{10x13}}+\frac{1}{\text{13x}16}$

( Write the result as a/b )

Calculate:

$\frac{1}{1\text{x5}}+\frac{1}{\text{5x9}}+\frac{1}{\text{9x13}}+....+\frac{1}{\text{73x77}}+\frac{1}{\text{77x81}}$

( Write the result as a/b )

Calculate:

$\left( 1+\frac{1}{2} \right)\times \left( 1+\frac{1}{3} \right)\times \left( 1+\frac{1}{4} \right)\times ....\times \left( 1+\frac{1}{49} \right)$

( Write the result as a/b )

Calculate:

 $\left( 1+\frac{1}{2} \right)\times \left( 1+\frac{1}{3} \right)\times \left( 1+\frac{1}{4} \right)\times ....\times \left( 1+\frac{1}{100} \right)$

( Write the result as a/b )

How many rectrangles in the figure below:

Calculate:

$\begin{align}& 100-\left( 1+\frac{1}{2} \right)\times \left( 1+\frac{1}{3} \right)\times \left( 1+\frac{1}{4} \right)\times ......\times \left( 1+\frac{1}{99} \right) \\&  \\\end{align}$

( Write the result as a/b )

How many rectrangles in the figure below:

Calculate:

$\left( 1-\frac{1}{2} \right)\times \left( 1-\frac{1}{3} \right)\times \left( 1-\frac{1}{4} \right)\times \left( 1-\frac{1}{5} \right)$ =…..?

( Write the result as a/b )

How many quadrangles in the figure below:

Calculate:

$\left( 1-\frac{1}{2} \right)\times \left( 1-\frac{1}{3} \right)\times \left( 1-\frac{1}{4} \right)\times ....\times \left( 1-\frac{1}{100} \right)$

( Write the result as a/b )