Câu 3: Trang 126 sách giáo khoa (SGK) toán tiếng anh lớp 4Two cars moved the rice from a warehouse...

If the first car transferred 200 kilograms of rice and the second car transferred 300 kilograms of rice, then both cars transferred a total of 500 kilograms of rice, which is $rac{5}{7}$ of the total amount in stock.

Assuming there are 70 parts of rice in stock, the first car transferred 20 parts and the second car transferred 30 parts. Therefore, both cars transferred a total of 50 parts of rice.

Let x be the total number of parts of rice in stock. The first car transferred $rac{2}{7}x$ parts and the second car transferred $rac{3}{7}x$ parts. Therefore, the total number of parts transferred by both cars is $rac{2}{7}x + rac{3}{7}x = rac{5}{7}x$.

The first car transferred $rac{2}{7}$ of the rice, which is equivalent to 2 parts out of 7 parts. Similarly, the second car transferred $rac{3}{7}$ of the rice, which is equivalent to 3 parts out of 7 parts. Therefore, both cars transferred a total of 5 parts of rice.

If the total amount of rice in stock is 7 parts, the first car transferred 2 parts and the second car transferred 3 parts, then both cars transferred a total of 5 parts of rice.