I urgently ask for help to do two primary school math questions, two simple primary school math prob

1 There were 460 apple trees, 315 peach trees, and 225 pear trees in the orchard. With an average area of 14 square meters per tree, how many hectares does this orchard occupy?

In common. 460 315 225 1000 (trees) The area of the orchard is:

14 1000 14000 (sqm) ha)2 The power bureau had to erect a 7,200-metre-long cable, which was planned to be completed in 12 days, but was actually completed in 9 days. How many meters more are actually erected per day than planned?

Actually done every day.

7200 9 800 (m).

The plan is completed every day.

7200 12 600 (m).

Actual more erections per day than planned.

800 600 200 (m).

2 The power bureau wanted to erect a 7,200-meter-long cable, and planned to complete the task in 12 days, but actually completed the task in 9 days. How many meters more are actually erected per day than planned?

1 (460 + 315 + 225) * 14 = (square meters) 2 (7200 12) This is how many meters are planned to be erected per day.

7200 9) This is the actual length of erection per day.

It's OK to reduce the two if you want to.

If there are x people in total, the number of apples is the same twice.

4x+18=5x-15

x=33 If A does 2x every day and B does 3x every day, then the total amount of work is (2x+3x)*10=50x

B takes 50x 3x=50 for 3 days.

(1) There were 48 people rowing in the fifth (1) class, and the 7 boats were just full. Each large boat seats 8 people, and each small boat seats 6 people. How many large boats and small boats are there?

Solution: Set up a big ship x strips.

8x+6（7-x）=48

x=3(2)2 yuan renminbi and 5 yuan renminbi have a total of 35 pieces, a total of 151 yuan, how many pieces of each of the two renminbi are there?

Solution: Set 5 yuan x sheets.

5x+2（35-x）=151

x=272 yuan: 35-27=8 sheets.

If you add a piece of sugar, it will be divided equally among 3 children, and it will be evenly divided into 5 children, at this time, the sugar is a multiple of 15, and it will be divided among 4 children, and 2 more pieces will be even. It must be an even multiple of 15. After verification, 30 are eligible.

Subtracting the additional pieces, there were at least 29 pieces.

The three people ran a lap in 60 seconds, 80 seconds, and 75 seconds. The least common multiple of the three numbers is 1200, and after 1200 seconds, or 20 minutes, the three meet at the place of departure.

1. A bunch of candies, if divided equally among 3 children, there are still 2 pieces left; If the average score is given to 4 children, there is still 1 piece missing; If it is divided equally among 5 children and there are 4 pieces left, how many pieces of candy are there in this pile?

Solution: It is equivalent to this pile of sugar, divided by 3 and 2, divided by 4 and 3, divided by 5 and 4. Then add one more piece to be the common multiple of .

3 4 5-1 = 59 blocks.

2. Three students A, B and C run around the ring track, it takes 1 minute for A to complete a lap, 1 minute and 20 seconds for B to complete a lap, and 1 minute and 15 seconds for C to complete a lap. Now the three of them set off at the same place at the same time, and at least a few minutes later the three of them met again at the place of departure.

Solution: Replace all the time into seconds, which are 60 seconds, 80 seconds, and 75 seconds. To meet again is to find their common multiples.

Using short division, they can be obtained with a minimum common multiple of 1200 seconds.

So it will take 20 minutes to meet again.

Solution: The first problem is divided by 3, 4, and 5 by adding 1 block to each of them, and there are at least 60 pieces, and the actual one less is 59 pieces. The second question is actually to find the least common multiple of 60, 80, and 75, which is 1200 seconds = 20 minutes, so we meet again at the starting point after 20 minutes.

1.If the length of a rectangular piece of land is increased by 4 meters, the area will increase by 80 square meters; If the width is increased by 4 meters, the area will increase by 200 square meters. How many square meters is the area of this land?

Length: 200 4 = 50 meters.

Width: 80 4 = 20 meters.

Area: 50 20 = 1000 square meters.

The area of the land is 1000 square meters.

2.A rectangle is 12 centimeters long, two-thirds wide, and has an area of (100) square centimeters with the same circumference.

Width = 12 2 3 = 8 cm.

Circumference of the rectangle = 12 2 + 8 2 = 40 cm.

Square side length = 40 4 = 10 cm.

Square area = 10 10 = 100 square centimeters.

1 Length: 50, Width: 20, Area: 1000 square meters.

2, 100 square centimeters.

1.The distance between the two places is 120 kilometers.

Went to use: 120 30 4 (hours).

240 40 6 (hours).

6-4 2 (hours).

120 2 60 (kmh).

2.The volume of a cuboid is 1560, its length, width and height are all natural numbers, and the sum of its edges and lengths is the smallest (160).

then the edge length is , and the minimum is (12 13 15) 4 160

1.If the distance between the two places is considered to be 1, then the round-trip distance is 2, so 2 40 is the average speed of 40, and the time required for a round trip, 1 30 is the time taken to go, so the speed at the time of return is:

1 (2 40 1 30) 60 km h 2Because 1560 2 2 2 5 39

And when the difference between the length, width and height of the cuboid is the smallest, the sum of the edge lengths is the smallest, so the length, width and height are respectively

Their sum is 8 5 39 52

Question 1, 60 km/h.

Question 2 35, 10 plus 12 plus 13

120 30 4 (hours).

240 40 6 (hours).

6-4 2 (hours).

120 2 60 (kmh).

A: Then you will sail 60 kilometers per hour on the return.

1560＝8x15x13

8+15+13)x4=144

Answer: The minimum sum of its edge lengths is 144

2 The volume of a box is 1560 units.