Tính chiều cao hình thang có:  
Diện tích 30cm²; đáy lớn 8cm và đáy bé 0,4dm ?

Trả lời: Chiều cao của hình thang là …..cm

Tính diện tích hình thang có :

Đáy lớn $\frac{2}{3}$ m; đáy bé $\frac{1}{2}$m; chiều cao $\frac{3}{5}$m ?

(Viết kết quả dưới dạng a/b)

Trả lời: Diện tích hình thang là: …..m2

Tính diện tích hình thang có :

Đáy lớn 1,9m; đáy bé 1,3m; chiều cao 0,9m ?

Trả lời: Diện tích hình thang là:…..m2

Tính diện tích hình thang có :
 Đáy lớn 8m; đáy bé 75dm; chiều cao 32dm ?

Trả lời: Diện tích hình thang là:…..dm2 

There are 540 lumber trees in a garden of 1000 trees, the rest are fruit trees.

What percentage of all trees in the garden are lumber trees ?

Class 5A planned to plant 180 trees. So far they have planted 45% of the target. How many more trees do they need to plant to meet the target ?

In a school of 400 students, there are 80 good students. Find the ratio of the good students to all students in the school ?

( Write the result as a/b )                                          

There are 315 schoolgirls in Van Tho Primary School out of all  600 students. Find the percentage of schoolgirls ?

According to the plan, Hoa An village has to plant 20 ha of corn this year. At the end of September Hoa An village planted 18 ha and at the end of the year, they planted 23.5 ha. At the end of the year how many percents of the plan did Hoa An village exceed the plan ?

A man spends a capital of 42 000VND on buying vegetables. After selling all the vegetables, he earned 52 500 VND. What percentage of the capital is revenue ?

A primary school has 800 students, 52.5% of which are schoolgirls. How many schoolgirls are there in that school ?

A garment factory uses 345 m of fabric to make shirts and trousers. The fabric used to make trousers accounts for 40% of the total amount of fabric. How many meters of fabric are used to make shirts ?

A rectangular parcel has a length of 18m and a width of 15m. They used 20% of the area to build a house. What is the area of the house ?

A man sold 120kg of rice, 35% of which are sticky rice. How many kilograms of sticky rice did he sell ?

Therer are 420 girls in a school, who account for 52.5% of all students. How many students are there in the school ?