2. Female: 70,000× 8000 ÷ (8000+6000) = 40,000 yuan.
Male: 70000×6000÷(8000+6000)=30000 yuan.
3. The personal income tax rate is 5%, and only the part exceeding 1600 is taxed.
(1790-1600) ÷ (100%-5%)+1600 =1800 yuan.
4.350×1/5 ÷ (1+2/5) = 50 trees.
5. Cars: 24/36=2/3
Bus: 12/36= 1/3
These are all questions about proportion, and the key to solving these problems lies in figuring out what is the total amount and what is the partial amount.
Find the number of parts from the known total: total × proportion = number of parts.
Find the total by knowing the partial quantity: partial quantity ÷ ratio = total quantity.
Find the ratio of the known total quantity to the partial quantity: partial quantity ÷ total quantity = proportion.
Some problems only have the relationship between the total quantity and the partial quantity, such as 1, 3,5, and the fifth problem is the relationship between the two partial quantities and the total quantity respectively, which can be regarded as two problems.
Some problems have the process of total quantity and partial quantity transformation, such as question 2 and question 4. The second question, first of all, is to find the proportion through two known partial quantities, and then find two corresponding partial quantities through the proportion and another total quantity. Question 4: Take the apple tree as the total, then the peach tree as the total, and then the orange tree as the total. This question also reminds everyone that the so-called partial quantity can be greater than the total quantity, and the "total quantity" is a benchmark and a denominator of 1; Partial quantity is a concept based on total quantity, and it is a molecule. Just as the numerator of a fraction can be greater than the denominator, the "partial quantity" can also be greater than the "total quantity".
If the landlord is a student, you can carefully understand the proportional relationship expressed in the topic, or use some things around you to learn more about what proportion is and how to use it.
If the landlord is a parent, I hope to guide the children to understand what proportion is.
Produced by Shirley Green.