Elementary School Math Problem Solving Process 5, Primary School Math Problem Solving Process

Trucks travel 75 kilometers per hour and buses travel 69 kilometers per hour, so trucks travel 75-69 = 6 kilometers more per hour than passenger cars.

When two vehicles meet 9 kilometers from the midpoint, it means that the truck has traveled 9 * 2 = 18 kilometers longer than the bus, and it has taken [9*2] (75-69) = 3 hours.

So the total distance is (75 + 69) * 3 = 432 km.

A, the two places are 432 kilometers apart.

I won't help you do the math

Set the encounter time to x

The total distance is (75+69)x

Half (i.e., midpoint) is (75+69) x 2

Because of the high speed of the truck, it travels half the distance plus 9 kilometers.

The column equation is 75x-(75+69)x 2=9

75x-72x=9

The solution is x=3, i.e., the encounter time is 3 hours.

So the total distance is (75+69) multiplied by 3 equals 432 kilometers.

Let A and B be x meters, the speed of the truck is faster than that of the bus, and the meeting place should be closer to B, so the travel distance of the truck is (x 2) + 9km, and the travel distance of the passenger car is (x 2) -9km, and the travel time is t

From the above: 75t = (x 2) + 9km, 69t = (x 2) - 9km, about t to get x = 432km

When two vehicles meet 9 kilometers away from the midpoint, it means that the truck has traveled 9*2=18 kilometers more than the passenger car.

Distance between two places: (75+69)*3=432

The distance between the two places is x kilometers.

x/2-9）/69=（x/2+9）/75

x-18）/2/69=（x+18)/2/75x-18)/69=(x+18)/75

x/69-6/23=x/75+6/25

x/69-x/75=6/25+6/23

75x/5175-69x/5175=138/575+150/5756x/5175=288/575

6x=288/575*5175

6x=288*9

x=288*9/6

x = 432 A is 432 km apart.

Trucks are fast and buses are slow.

6 kilometers more per hour.

After the encounter, the truck went 9 9 18 (km) more

Time to meet: 18 6 3 (hours) Distance between the two places:

The speed ratio of A and B is.

B to A completed the journey, A traveled the whole journey 2 3

When they meet, the time taken by A and B is the same, because the speed of the two is different, so the distance traveled is not the same, that is, the speed ratio of A and B is 4:6=2:3.

And when a has been reached, B has traveled the distance of ab, that is, the required amount s, so according to the same time, the ratio of distance is equal to the ratio of velocity, which can be columned: 2:3=390:

s, i.e., s=390*(3 2).

A and B are 435 km apart.

Analyze: When A and B meet, A travels 40 percent, then B should be 60 percent, and the speed ratio of A and B is 2:3

When B reaches place A, A has traveled a total of 390 kilometers, and the speed ratio in the same time is equal to the distance ratio, then B has traveled 435 kilometers, which is the distance of AB.

When A and B meet, A travels 2 5 and B travels 3 5, that is, the ratio of A and B trips in the same time is 2:3. When B arrives at place A, A has traveled the whole journey (1x2) 3, and the question tells you that A has traveled a total of 390 km, then the whole distance is 390 (2 3) = (390x3) 2 = 585km.

This is the distance between abs.

The ratio of the speed of A to B is 4:6 (because A has traveled 40 percent and B has traveled 60 percent).

The ratio of distance between A and B is also 4:6 (the same time).

So s = 390 * (4 6) = 390 * (3 2) = 585 km.

Solution: If the probability of winning the lottery is x, then there is.

1000000x=10+100+1000

x=1110/1000000

Solution: Set the price to drop by x yuan, then.

2(15-x)-15) 15=1 5, solution equation: x=6

Suppose the number of people on the original bus is x, get off 20% after arriving in Tianjin, and 80% x is on the bus. 48 people come up, then there are 80% x + 48 in the car and the number of people x in the original car is not 7:8.

Equation: (80%x+48): x=7:

8；The solution is x=640, so Tianjin gets off 20%*640=128 people.

x-20%x+48:x=7:8

The solution is x=640 20%x=128

128 people got off at Tianjin Railway Station.

Let the total number of people be x

then the equation (x=48*8 people).

The number of people who get off the bus from Tianjin = people).

Check: (

Let the number of people in the original car be x

1-20%)x+48=7/8x

4/5x+48=7/8x

7/8x-4/5x=48

35/40x-32/40x=48

3/40x=48

x=48x40/3

x=640640x20%=128

That is, the number of people in the car is now 7 8

And the number of people who got off the bus was 1 to 5

So the number of people who get on the bus is the original 7 8 - (1-1 5) = 3 40, so the original number of people on the bus is 48 3 40 = 640, then the number of people who get off the bus is 640 1 5 = 128 (people).

There turned out to be in the car:

48 (7 8 + 20% -1) = 640 people.

Get off in Tianjin: 640 20% = 128 people.

It is known that the area of the circle is equal to the area of the rectangle, the circumference of the circle is centimeters, the length of the short side of the rectangle is equal to the radius of the circle, and the circumference of the shadow part is the sum of the lengths of the four parts: one long side, one short side, the long side of the radius of the circle truncated, and the circumference of one of the four winds.

Let the circumference of the circle be i, the radius of the circle, i.e., the length of the short side of the rectangle, the length of the long side of the rectangle, the length of the shaded part of the long side of the rectangle truncated by the circle is l, the area of the circle, i.e., the area of the rectangle, is s, and the circumference of the shadow part is c.

Then, from the circumference formula 2 r, the radius of the circle r=i 2 = cm) from the circle area formula r, the area of the circle = the area of the rectangle = s= ·4 = square centimeters) there is the formula of the area of the rectangle length height It can be seen that the long side of the rectangle d=s r=cm) the length of the shadow part of the long side of the rectangle truncated by the circle l=d-r=cm) the shadow perimeter is c=d+r+l+i 4=

centimeters) from this, the circumference of the shaded part is centimeters.

The circumference of the circle is, then the radius = , i.e. the area of the circle = 4

The area of the circle is equal to the area of the rectangle, so the area of the rectangle = and the width of the rectangle is 4, that is, the length of the rectangle =

Therefore the perimeter of the shadow part =

Solution: The radius of the circle:

The area of the circle: the length of the rectangle:

Perimeter of the shaded part: (==.)

The radius of the circle: cm.

It is also the width of the rectangle, and the area of the rectangle is 3 4 of the area of the circle and the length of the rectangle: 4 cm.

The circumference of the shaded part is the sum of 2 strips and 1 4 of the circumference of the circle.

When divided into infinitely many parts, the circumference of the assembled rectangle is approximately twice the radius of the circumference of the circle. When I was in elementary school, there was a plastic model that looked like two semicircles cut into watermelons, and then put together like a rectangle.

2pi*r+2*r=, can have r=2, and the area is pi*r*r=.

The circumference of an approximate rectangle is the circumference of the circle plus two radii (one diameter), so the approximate is a multiple of the diameter.

So the diameter: area is 2 = square centimeters.

1 A + 1 B = 1 4

1 B + 1 C = 1 6

1 A + 2 B + 1 C = 1 6 + 1 4 = 10 24 = 5 121 A + 1 C = 5 12-2 B.

2*(1 A+1 C)=2*(5 12-2 B)=10 12-4 B1-2*(1 A+1 C)=7 B=1-(10 12-4 B)3 B=2 12

B = 18 B does this work alone and completes it in 18 hours.

(1-2/4-2/6）÷（7-2-2）

18 (hours).

The key to solving the problem: divide B's working time into segments: 2 hours with A, 2 hours with C, and the rest of the work is completed independently for 3 hours.

When they meet, the distance ratio of the two cars is 3:2, that is, the speed ratio of the two cars is 3:2, then.

Vehicle B speed = A speed * 2 3 = 72 * 2 3 = 48 km h.

Distance = 48 20% = 240 km.

When encountering, car A passes = 1 * 3 5 = 60% of the whole journey.

Car B goes through = 1 * 2 5 = 40% of the whole process.

Elapsed time = 40% 20% = 2 hours.

The speed of car B = 72 * (2 3) = 48 kilometers Hour AB distance between two places = 2 (72 + 48) = 240 km AB The distance between two places is 240 km.

When they meet, B performs the whole course: 2 (2+3)=2 5

20% of the entire journey of Line B per hour

Encounter time: 2 5 20% = 2 hours.

A line: 72 2 = 144 km.

ab distance: 144 3 (3+2) = 240 km.

When the two cars meet, A walks 3 5 of the whole journey, B walks 2 5 of the whole journey, B walks 1 5 of the whole journey per hour, and the time it takes them to meet is 2 5 1 5 = 2 hours, then A walks 72 2 = 144 kilometers, and the whole journey is 144 3 5 = 240 kilometers.

The two cars travel for the same amount of time, so the distance ratio is equal to the speed ratio

Let the distance between A and B be S kilometers.

72:20%s=3:2

s=240

Set the price of tickets to be reduced by X yuan, and there were originally audience Y people. The original income is 15y, and the income after the price reduction increases by one-fifth, and the income after the price reduction is 15y+15*1 5=18y. The number of spectators after the price reduction is y+y*1 2=3 2yAt this time, the ticket price after the price reduction is 15-x, so the income after the price reduction is 3 2y(15-x)=18y, and the moving equation is 18y divided by 3 2y=15-x, because y is not equal to zero, so y can be eliminated, that is, it is reduced to a one-dimensional equation, 12=15-x, x=3.

So the price of a ticket is reduced by 3 yuan.

Mine is the correct answer, you can take it back to verify, the previous one is wrong.

Set a price reduction of x yuan, the original audience y people, income w yuan.

15-x)* now).

15xy=w (original).

Divide the two equations to get x=15 13

Answer: The price is reduced by 15 to 13 yuan.

Algebra isn't taught in elementary school, so you can't use algebra.

Original income = original ** original number of people.

Current income = current ** 2 original number of people.

Current income - original income) Original income = 1 5

That is, (now**2 original number of people - original** original number of people) original** original number of people = 1 5 approximate (now** 2 - original**) original**=1 5 original**=15 so now**=9

That is, the price is reduced by 6 yuan.

Hello, set the original audience to m people, and reduce the price by n yuan.

15m=2m（15-n)-15/5m

15m=30m-2nm-3m

15m=22m-2nm

2nm=6m

n=6A: The price of a ticket is reduced by 6 yuan.

Let the price drop be x, then (2(15-x)-15) 15=1 5, and solve the equation x=6