1. A primary school planted 585 trees in the third, fourth and fifth grades. The number of plants in grade 4 is 65438+0.5 of that in grade 5, and the number of plants in grade 3 is 3/4 of that in grade 5. How many trees are there in grade three? 2. The number of rainy days in July is 8/ 1 1 less than that in sunny days, and the number of cloudy days is 3/22 of that in sunny days. How many rainy days are there this month? 3. Grade 5 students in a school 152 students. Boys' 65,438+0/65,438+065,438+0 were selected to take part in the math contest with five girls, and the remaining students were just equal. How many boys and girls are there in this class? There are two 44m long iron wires. If the first one is cut 1/5 and the second one is connected 2.8m, then the two lines are equal. How long are these two wires?

Answer: Grade 3 is 3/4*300=225, Grade 4 is 300* 1/5=60, and Grade 5 is 300.

If someone rides a bike from home to the train station, if they drive at the speed of15km per hour, they can arrive15min earlier than the train departure time. If he drives at 9 kilometers per hour, he will arrive 15 minutes later than the departure time. Now he plans to arrive 10 minutes earlier than the departure time. How many kilometers should he drive every hour?

Answer: the distance between the two places is:15 * [1-15/60] =11.25km.

Then arrive 10 minutes in advance, and one hour should be enough:11.25/[1-kloc-0/0/60] =13.5km.

The canteen buys flour and rice, which is twice as heavy as rice. It eats/kloc-0.5 kg of rice and 20 kg of flour every day. A few days later, all the rice was eaten, leaving 80 kilograms of flour. How many Jin of rice and flour does this canteen buy?

Suppose that it takes X/ 15 days for x kg of rice and 2X kg of flour, so there is 20*(X/ 15)+80=2X, and the solution is X= 120. So there are 120 Jin of rice and 240 Jin of flour.

The following one is easier.

1:A train travels 10 hour, B train travels for 7 hours, and A train travels 276 kilometers more than B. If the two trains have the same speed, find the speed of the two trains.

Chen and Zhang ride bicycles from the same place in opposite directions at the same time. After 0.5 hours, the distance is 12.5 kilometers. Chen's speed is 12 kilometers per hour. How many kilometers is Zhang's speed? (party)

3. The number of bookcases sold by the furniture factory is one fifth of that of five X cabinets, and the number of bookcases sold is less than that of five X cabinets 120. How many bookcases and five X cabinets were sold? (party)

4. Make a rectangular iron suitcase with a capacity of 60 square decimeters. The length of the bottom is 4 decimeters, the width is 3 decimeters, and what is the height? (party)

5. The master processed 80 parts, which was less than the two companions processed by the apprentice 10. How much has the apprentice processed? (party)

6. The apprentice processed 45 parts, 5 more than half of the master. How much did the master process? (party)

Answer:

1.A X B Y

10X-7Y=267

10/X+7/Y= 1

2. Zhang x

( 12+X)*0.5= 12.5

3. Bookshelf x five cabinets y

X= one fifth *Y

X=Y- 120

4. high x

4*3*X=60

5. Apprentice X

2X- 10=80

6. main x

Half *X+5=45