5. Solution: Suppose that X bicycles have been sold at this time. According to the meaning of the question, you can get:

275 times > 250×200

The solutions are x > 18 1 and 9/ 1 1 because x is

Integer, so the minimum value of x is 182.

A: At least 182 bicycles have been sold.

6. solution: it takes x m to set the fuse. According to the meaning of the question, it is:

x/0.0 1≥400/5

x≥0.8

Answer: The fuse should be at least 0.8m.

7. Solution: Assume that the annual profit of the whole factory in the previous year was X million yuan. According to the meaning of the question,

Get:

(x+100)/(280-40)-x/280 ≥ 0.6, so x≥308.

A: The annual profit of the whole factory in the previous year was 3.08 million yuan.

8. solution: set it at one kilogram of an apple, and the price is B yuan. According to the meaning of the question,

Get: 1.5a≤( 1-5%)a? B So, b≥30/ 19.

Answer: The price should be at least 30/ 19 yuan to avoid losing money.

(Note: 30/ 19 should be expressed as: 1 and119).

9. Solution: Suppose there are X computers sold at 5000 yuan/set. According to the meaning of the question, we can get:

5500× 60+5000x > 550000, so X > 44, so 60+44= 104 sets.

A: There are at least 104 computers in this batch.

Page 134 Exercise 3

Solution: Suppose that roads will be built for an average of X kilometers every day in the next few days.

Meaning: 6x≥6- 1.2, and the solution is x≥0.8.

A: In the next few days, at least 0.8 km of roads will be built every day on average.