The first group of Class One, Grade Six planted trees. If everyone plants 5 trees, there will be 14 trees left. If there are seven trees for each race, there will be four fewer trees. How many people are there in this group? How many trees are there?

Solve by arithmetic:

Number of people: (14+4)/(7-5)=9.

The idea is this: after each person plants five trees, there are 14 trees left. If everyone plants two more trees, there will be four fewer trees. That is to say, if four trees are added to the original number of trees planted, each person will have two more trees, then each person will have two more trees, and each person will have a variety of 18 trees, so the number of people is 18/2 =

How many more trees to plant:

9 * 5+ 14 =59 or 7 * 9- 4= 59

Give the children a bag of candy. If you give five dollars to the children in the big class, you are short of six dollars. If you give four dollars to the children in the small class, you will be short of four dollars. It is known that the big class is short of two children. How many pieces of sugar are there in this bag?

(6+4+4× 2) ÷ (5-4) = 18 (person) (large class size)

18+2 = 20 (person) (small class size)

18× 5-6 = 84 (block)

Solution: Assuming that there are as many people in the small class as there are in the large class, then each person in the small class will be given 4 pieces of sugar, and then the original 4 pieces will be added to the assumed 8 pieces.

Answer: 84 people

Solution: (6+4+4 * 2)/(5-4) = 18 students (large class)

18+2 = 20 people (small class size)

18 * 5-6 = 84 or 20 * 4+4 = 84.

Note: The key is to understand the meaning of 4+4*2, which means that if there are as many small classes as large classes, each small class can get an extra * * * (4+4*2) by giving 4 pieces.

Xiaoming went to the store to buy exercise books. If he bought eight books, he would have 1 yuan left. If he bought 12 books, he still needs one yuan. How much is each exercise book? How much did Yi Ming Jr. bring?

These two comparisons still have 1 yuan, which is one yuan short, so the price difference before the two comparisons is 2 yuan, but I bought 12-8=4 copies.

That is to say, four books use 2 yuan, so one is 2/4=0.5 yuan.

8*0.5+ 1=5 yuan

Or 12*0.5- 1=5 yuan.

Teach students to play ball. Work in pairs. 6 balls per component, less than10; Each component has 4 balls, 2 less. * * * How many groups are there? How many balls are there?

* * * How many groups are there

( 10-2)÷(6-4)

CoCo Lee's father sold a man two coats, A and B, at the same time. The selling price is A yuan, of which A coat makes a profit of 25% and B coat loses 25%. Please calculate whether this business is a loss or a profit. If so, how much?

Yes, I lost 2a/ 15.

The cost of A and B is 2a+2a/ 15.

Profit means 25% more than cost, and loss means 25% less than cost.

The cost of a: a/(1+25%) = four fifths of a.

Cost of B: A/(1-25%) = four-thirds of A.

The cost of both is 4/5a+4/3a=32/ 15a= 2 and 2/ 15 A.

Moreover, two clothes are only 2a, so they are losing money.

3. There is a rectangle with a volume of 102 cubic decimeter. If the length, width and height are prime numbers, what is the surface area of this cuboid? (Calculation formula)

1.The number of books in group A is three times that of group B. If group B gives six books to group A, the number of books in group A is five times that of group B.. How many books are there in Group A?

2. It turns out that Xiao Ming's picture is three times that of Xiao Hong, and then they each bought five, so Xiao Ming's picture is twice that of Xiao Hong.

1. You should have learned the hypothesis, right?

Suppose group B has X books and group A has 3x books.

5(X-6)=3x+6

X= 18 A has 54 copies.

Suppose the little red one is X, then the little red one is 3X.

2(X+5)=3X+5

X=5 Xiaohong, 5 books, Xiaoming 15 books.

2. The divisor quotient of two numbers is 8, the dividend. The sum of divisor and quotient is 170. What is the dividend?

2. 170-8= 162 162/(8+ 1)= 18 18*8= 144

8. There is a rectangular playground. If its length and width are increased by 6 meters, the area will increase by 1, 236 square meters. What was the circumference of the original sports ground?

9. Uncle Liu bought two baskets of apples, each with the same number of apples. Basket A sold 150, and basket B sold 194. The remaining apple baskets are three times as many as those of B. How many apples are there in each basket?

9. 194- 150=44 (piece) 44/(3- 1)=22 (piece) 194+22=2 16 (piece)

8. 1236-6*6= 1200 (square meters) 1200/6*2=400 (meters)

Xiao Li and Xiao Jie rode bicycles and walked in opposite directions from two places 65 kilometers apart. Xiaoli's speed is 15km/h, and Xiaojie's speed is 17.5m/h, 32.5km apart. How many hours have passed?

(This question is a topic of classified discussion, so we should discuss it in categories, so please ask experts to answer it, learn the process and do it well. )

In the first case, two people haven't met (at this time, the sum of the distances traveled by two people is (65km-32.5km).

(65km-32.5km)/(15km/h+17.5m/h) =1hour.

In the second case, after meeting, they walked 32.5 kilometers. (At this time, the sum of the distances traveled by two people is 65km+32.5km)/

(65km+32.5km)/( 15km/h+ 17.5m/h)= 3h。

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