Calculate:

$\frac{1}{3}+\frac{2}{4}=$ …? (The result is the simplest fraction as a/b)

Two buckets contain total 216 kg rice. Know that if the first bucket transfers 15 kg to the second bucket, the number of rice in two bucket is the same.  How many kilograms do each bucket have? 

Hung and Dung have total  46 marbles. If Hung gives for Dung 5 marbles, Hung has 14 marbles more than Dung. How many marbles each person have at first ?

4A class and 4B class have total 82 students. If 2 students are transfered from 4A to 4B, the number of student in two class is the same. Find the students in each class ?

Two bucket contain total 116l. If transfering 6l from the first bucket to the second bucket, two bucket have the same lits. How many lits does each bucket have ? 

An and Binh have total 120 marbles. If An gives for Binh 20 marbles, Binh will be 16 marbles more than An. How many marbles do each person have?

Tim has 22 marbles consist of red marble and blue marble. Tim gives for his brother 3 red marbles and 2 blue marbles.Then John gives for Tim 7 red marbles. So,the number of red marble is 2 times the number of blue marble. How many blue marbles does Tim have at first ?

Two buckets contain total 10 tons rice. Know that if the first bucket transfers 600kg to the second bucket, the number of rice is the same. How many kilograms are there in first bucket?

The sum of two numbers is 713. If the greater number is decreased 26 units, the greater number will be 21 units more than the smaller smaller. Find two numbers?

Two bucket contain total 428l. If transfering 24l from the first bucket to the second bucket, the second bucket will be 6l more than the first bucket. How many tons does the second bucket contain ?

Two buckets contain total 178 kg rice. Know that if A bucket transfers 24 kg to B bucket, the number of rice is the same.  How many kilograms are there in B bucket ?

The even number sequence:
2; 4; 6; 8;…?
The number 1996 is ${{n}^{th}}$ terms of the sequence. Tìm n ?

The odd number sequence : 1; 3; 5; 7;…

The number 399 is  terms of the sequence?

How many terms are there in the sequence?

0; 2; 4; 6; 8; …; 2008; 2010

Find the sum of all terms in the sequence:

0; 2; 4; 6; 8; …; 2008; 2010?