1. The patrol car travels 200 kilometers every day, and each patrol car can be loaded with gasoline 14 days. At present, there are five patrol cars, starting from place A at the same time. In order to let the three of them patrol as much as possible (and then return together), after arriving at B, Party A and Party B only leave enough gasoline for themselves to return to the base, and the surplus gasoline is supplied to other cars. What is the longest driving distance of the other three cars?

A and b run for 4 days. Leave four days of oil for the return trip, and the remaining 12 days of oil for the other three cars, so that the other three cars can run for five days, so that they can run as far as possible.

200 km times 9 equals 1800 km.

2. The sum of the ages of Party A and Party B this year is 63. When Party A's age is half of Party B's present age, Party B is exactly Party A's present age. How old is A and B this year? One: Solution: Suppose A is X years old this year and B is Y years old this year.

x + y = 63

y-(x- 1/2 y)= x

Solve it and get it.

x = 27

y = 36

A: A is 27 years old and B is 36 years old.

Two: Solution: Suppose A is X years old this year and B is Y years old this year. M years later, A is half the age of B this year.

x + y = 63

x + m = 1/2 y

y + m = x

Solve it and get it.

x = 27

y = 36

A: A is 27 years old and B is 36 years old.

Solution: Suppose B is x years old this year, then A is (63-X) years old this year.

1/2 x-(63-x)= 63-2x

X = 36 is obtained by solving.

So 63-x = 63-36 = 27.

A: A is 27 years old and B is 36 years old.

Student 4: Solution: According to the meaning of the question, the age of getting a B this year is:

63÷ (1/2÷ 2+1/2+1) = 36 (years old)

So A's age this year is 63-36 = 27 (years old).

A: A is 27 years old and B is 36 years old.

3. A national ministry has three organs, A, B and C, and the civil servants of these three organs are 88, 52 and 60 in turn. This year's institutional reform requires the three organs to lay off employees in the same proportion, and there are still 150 civil servants left in the three organs. So how many people are left in the C organ?

Solution1:x+52x/60+88x/60 =150, then x=45.

Solution 2: X+52x/60+88x/60 = (88+52+60)-150 Then x= 15.

4. Make a copy of the material. If you copy 30 words per minute, you can finish it in a few hours. When you copy to 2\5, the work efficiency will be increased by 40% due to changing the method. In this way, you can finish it half an hour in advance. How many words are there in this material?

If this material * * * has an X, then: X/30-30 = (X/30) * (2/5)+(X * 3/5)/(30 *140%).

Solution: x=5250

5. There are 400g of saline water with salt content of 15%. Teacher Zhang requires that the salt water concentration be 12%. A classmate added 1 10g water after calculation. Please verify whether the amount of water added by your classmates is correct by solving the equation.

Suppose x grams of water is needed, then: (400+x) *12% = 400 *15% gives x= 100.