Example 1
In 2016, the output value of traditional manufacturing and emerging manufacturing industry in a city totaled 83 billion yuan, and in 2017, the city further promoted the transformation of output value, the output value of traditional manufacturing industry decreased by 6% year-on-year, and the output value of emerging manufacturing increased by 15% year-on-year, and the total output value of traditional manufacturing and emerging manufacturing increased by 3 billion yuan compared with last year, and the output value of emerging manufacturing industry in the city increased to 55 billion yuan in 2018.Solution:In 2016, the output value of the traditional manufacturing industry was X billion yuan, and the output value of the emerging manufacturing industry was Yi billion yuan.a.12%b.20%
c.26%d.34%
According to "the output value of traditional manufacturing and emerging manufacturing industries in 2016 totaled 83 billion yuan", the equation can be listed: x+y=830.
According to "the output value of the traditional manufacturing industry in 2017 decreased by 6% year-on-year", and the emerging manufacturing industry increased by 15% year-on-year in 2017", the total output value of the traditional manufacturing industry and the emerging manufacturing industry increased by 3 billion yuan compared with last year", which can be listed by the equation: -006x+0.15y=30โกใ
Syndicate, the solution is x=450, y=380.
In 2017, the output value of the emerging manufacturing industry was 380 (1 + 15%) = 43.7 billion yuan.
In that year, the output value of the emerging manufacturing industry increased by (550-437) 437 26%.
So, choose option C.
Example 2
Xiao Wang went to a certain unit to do business, there was only one window to handle business, Xiao Wang ranked 6th, and the first customer started to handle business at 9:02. If the processing time of each order is 6 minutes, and the person in front of Xiao Wang will not leave early. So when can Xiao Wang start business?Solution:According to "Xiao Wang ranks 6th", it can be seen that there are 5 customers in front.a.9:32
b.9:38
c.9:45
d.9:52
According to the "processing time of each order is 6 minutes", it can be seen that it takes 6 5 = 30 (minutes) for the first 5 people to complete the whole process.
According to "the time for the first customer to start handling business is 9:02", it can be seen that Xiao Wang starts handling business at 9:02+30=9:32.
So, choose option A.
Example 3
In response to the call to promote the great development and prosperity of China's socialist cultural undertakings, a community decided to prepare 40 yuan of culture for each elderly person in the community, and at the same time prepare 20 yuan more culture for each child than the elderly. It is known that there are 100 more elderly people than children in the community, and the cultural ** is a total of 14,000 yuan, so the total number of elderly and children in the community is:Solution:If there are x children in the community, there will be (x+100) elderly people.a.300b.320
c.360d.480
According to the meaning of the problem, the equation can be listed: (40+20)x+40(x+100)=14000.
Solution x=100.
The total number of elderly and children in the community is: 100 + (100 + 100) = 300 (people).
So, choose option A.
Example 4
There are two fruit baskets A and B on the table, there are 40 apples and 10 pears in basket A, 33 apples and 47 pears in basket B, take out some fruits from basket B and put them in basket A, and find that the ratio of the number of apples and pears in basket A becomes 7:3, and basket B becomes 2:3, then a total of () fruits are taken out from basket B and put into basket A.Solution:According to "take out some fruits from basket B and put them in basket A, and find that the ratio of the number of apples and pears in basket A becomes 7:3", it can be seen that the total number of fruits in basket A is a multiple of 7+3=10.a.15b.20
c.25d.30
At this time, the total number of fruits in basket A = the number of fruits in the original basket A + the number of fruits taken out of basket B.
The original number of fruits in basket A: 40 + 10 = 50 (pieces), is a multiple of 10, then the number of fruits taken out from basket B should be a multiple of 10.
Substituting option b:
If a total of 20 fruits are taken out from basket B, the total number of fruits in basket A is 50 + 20 = 70 (pieces).
At this time, the total number of apples in basket A is 70 (7+3) 7=49 (pcs), and the total number of pears in basket A is 70-49=21 (pcs).
The number of apples in basket A increased by 49-40 = 9 (pcs), and the number of pears in basket A increased by 21-10 = 11 (pcs).
There are 33-9 = 24 apples left in basket B, and 47-11 = 36 pears left in basket B.
At this time, the ratio of apples and pears in basket B is 24 36 = 2 3, which is in line with the title.
So, choose option B.
Example 5
A factory needs to use A, B, C three kinds of parts in the production process, the original three parts in the factory warehouse quantity ratio of 1 2 3, now the purchasing department purchases a new batch of parts, the number ratio of the new purchase of three parts is 3 2 4. The factory uses the same number of three parts every day, when the A part is used up, there are 10 B parts left, and 170 C parts left, how many A, B, and C parts are left in the factory warehouse?Solution:According to the "ratio of the quantity of the original three parts in the factory warehouse is 1 2 3", the number of the original three parts can be set to x, 2x, and 3x.a.40 80 120
b.50 100 150
c.60 120 180
d.70 140 210
According to "the quantity ratio of the three newly purchased parts is 3 2 4", the quantity of the newly purchased three parts can be set to be 3y, 2y, and 4y respectively.
According to "the same number of three parts used in the factory every day, when part A runs out, there are 10 parts left in B and 170 parts in C", the equation can be 2x+2y-x-3y=10;3x+4y-x-3y=170ใ
Solving the system of equations yields x=60, y=50.
Therefore, there were 60 parts A in the factory warehouse, 2 60 = 120 (pieces) of B parts, and 3 60 = 180 (pieces) of C parts.
So, choose option C.