We have:

\(1-\dfrac{2013}{2014}=\dfrac{1}{2014}\) ;

\(1-\dfrac{2016}{2017}=\dfrac{1}{2017}\)

Because we see: \(\dfrac{1}{2014}>\dfrac{1}{2017}\) should : \(\dfrac{2013}{2014}< \dfrac{2016}{2017}\)

\(\left(\dfrac{1}{1.2}+\dfrac{1}{2.3}+\dfrac{1}{3.4}+...+\dfrac{1}{49.50}\right).x=1\)

\(\left(1-\dfrac{1}{2}+\dfrac{1}{2}-\dfrac{1}{3}+\dfrac{1}{3}-\dfrac{1}{4}+...+\dfrac{1}{49}-\dfrac{1}{50}\right).x=1\)

\(\left(1-\dfrac{1}{50}\right).x=1\)

\(\dfrac{49}{50}\cdot x=1\)

\(x=1\div\dfrac{49}{50}\)

\(x=\dfrac{50}{49}\)

So x = \(\dfrac{50}{49}\)

We have :

6 kangaroos eat 6 sacks of gian in 6 minutes .

=> 1 kangaroos eat 1 sacks of gian in 1 minutes .

From there we have:

100 kangaroos eat 1 sacks off grass in 100 minutes .

The :

 18 . 3 = 54 ( pencils )

                  Ans : ... 

The distance on the 1: 500 map is

 37 : 500 = 0,074 ( m )

                    Đáp số : 0,074 m

Number of user after :

 8 + 4 = 12 ( people )

12 people are 8 times the number is:

 12 : 8 = \(\dfrac{12}{8}=\dfrac{3}{2}\)( rolling )

The number of days the new crew need to build the same wall is :

 6 : \(\dfrac{3}{2}\)= 4 ( days )

                 Ans : ... 

The last digit of the product 3x5x7x9x11 is :

 3 . 5 . 7 . 9 . 1 = 945 => The final number is 5

                                                Ans : 5 

75 + 25 + 13 + 91 + 87 + 52 + 48 + 9

= ( 75  +  25 ) + ( 13 + 87 ) + ( 91 + 9 ) + ( 52 + 48 )

= 100 + 100 + 100 + 100

= 100 . 4

= 400

The contest Kangaroo in 2006 is the : 
 ( 2006 - 1991 ) : 1 + 1 = 16 ( ^th )

Select the response B!!!

The mean of these 6 numbers is:

 (456 + 465 + 546 + 564 + 645 + 654 ) : 6 = 555

                                             Answer : 555

The cubic volume is large :

 10 . 10 . 10 = 1000 ( cm³ )

Cubic cubic volume is:

 1 . 1 . 1 = 1 ( cm³ )

Dress :

 1000 : 1 = 1000 ( cube cubes )

                             Đáp số : . . .

What's wrong, sorry!!! 

The is : 12 . \(\dfrac{3}{4}\)= 9 ( liter )

Dress : 9 - 4 = 5 ( liter )

So answer A is true  !!!

Summer Clouds

20 x (0 + 6) - (20 x 0) + 6 

= 20 x 6 - 0 + 6

= 120 - 6

= 114 

Hence,the answer is A