It costs 1 / 3 of the total money to use a pen and 4 yuan to buy a story book. At this time, the ratio of the money spent to the rest is 5:4. What is the original money? How to write this question?

Let the original amount of money be X
The amount of money used is 1 / 3 × x + 4, and the rest is X-1 / 3 × x-4
The equation is as follows: (1 / 3 × x + 4) ∶ (x-1 / 3 × x-4) = 5 ∶ 4
x＝18

It costs 1 / 3 of my money to buy a pen and 4 yuan to buy a story book. The ratio of the money spent to the rest is 5:4

If the remaining money is x yuan, then
5:4=（x/4*9*1/3+4):X
X = 8 yuan
The rest is less than 8 yuan

1. Select 3 numbers from the following number cards to form a three digit number
1、0、2、5
The number of components is odd:
The number of components is even:
The number of components is a multiple of 2
The number of components is a multiple of 5
The number of components is a multiple of 3
The number of components is not only a multiple of 2 and 3, but also a multiple of 5

The number of components is odd: 105, 125, 201, 205, 215, 251, 501, 521
The number of components is even: 102, 120, 150, 152, 210, 250, 502, 510, 512, 520
The number of components is a multiple of 2: 102, 120, 150, 152, 210, 250, 502, 510, 512, 520
The number of components is a multiple of 5: 105, 125, 205, 215
The number of components is a multiple of 3: 102, 105, 120, 150, 201, 210, 501, 510
The numbers are not only multiples of 2 and 3, but also multiples of 5: 120, 150, 210 and 510
(warm tip: 0 can't be the first.)

To calculate the formula) 2
1. The coal carriage is a cuboid carriage with a length of 2.5 meters, a width of 1.8 meters and a height of 0.6 meters. How many cars are needed to transport 54 cubic meters of coal?
2. A cuboid fish tank is 30 cm long and 20 cm wide. When 4.5 liters of water is poured into the tank, it just accounts for half of the volume of the tank. How many cm is the height of the tank?
3. If class 3 of grade 6 takes part in the voluntary labor, if there are five people in a group, nine people in a group or 15 people in a group, and there are no remaining people, how many people are there in this class at least?
4. The two cars leave from two places 360 kilometers apart at the same time. Car a travels 33 kilometers per hour, while car B travels 6 kilometers more than car A. when the two cars meet on the way, how many kilometers does car a travel more than car B?
5. The distance between AB and B is 280 km. Two cars of a and B run from each other at the same time. After 4 hours of meeting, car a runs 36 km per hour on average. How many km per hour does car B travel?
6. A and B go from a to B at the same time. A travels 64 kilometers per hour. Five hours later, a is 78 kilometers in front of B. how many kilometers per hour does B travel?
If the answer is perfect, add extra points (+ - × / hope to use this)

(1) 54 (2.5 × 1.8 × 0.6) = 20 (2) the first unit centimeter turns into meter 4.5 × 2 (0.2 × 0.3) = 150 (3) find the common multiple of 5915 45 people (4) a 33 km, then B 39 km and speed 72 km meet time 360 △ 72 = 5, speed 39-33 = 6, distance 6 × 5 = 30 (5) let B's speed be X

How many liters per second is one cubic meter per day?

1 day = 24 * 3600 = 86400 (seconds)
1 cubic meter = 10 ^ 3 liters
1 m3 / D = 10 ^ 3 / 86400 = 0.011574 L / S

In the triangle ABC, ab = AC, the center line BD on the side of AC divides the perimeter of the triangle into two parts of 12cm and 15cm, and calculates the length of each side of the triangle?

According to the meaning of the question: the original perimeter of the triangle ABC is 15 + 12 = 27cm, there are two solutions (1), as shown in Figure 1: let AB = AC < BC, ab = AC = x; then there is ab + ad = x + & amp; frac12; X = 12. Solving this equation, we get x = 8, that is, ab = AC = 8, BC = 27-2 × 8 = 11, which conforms to the condition of triangular trilateral relationship

How to calculate 10-12 and 1 / 10 of 101 / 121?

101/(10/121)-121/10
=101*121/10-121/10
=121/10(101-1)
=121/10*100
=121*10
=1210

How to add the operation symbol of four eights equal to four

There are the following methods: 1. 8 ^ [(8 + 8) ^ (8)] = 4 / 2, 8 × [8 ^ (8 + 8)] = 43, 8 × 8 ^ (8 + 8) = 4

People's education press junior high school mathematics learning and evaluation seventh grade volume I answers, little girl thank you heroes, mathematics Oh!

Although it's a little damaging, our class has tried it, but it's still successful. Several people go to Xinhua Bookstore together, surround one person, tear down an answer, and then quickly hide it, and then go to the bookstore for a while, or wait for the teacher to steal an answer
I haven't practiced all of the above. Success depends on your luck!

33 out of 14, 34 out of 15, 35 out of 16, 36 out of 17, 37 out of 18
Compare the size of a column: 33 out of 14, 34 out of 15, 35 out of 16, 36 out of 17, 37 out of 18
Is there any rule in comparing sizes?

The difference between the numerator and denominator is 19, so the numerator is divided into 14 + 19,15 + 19,16 + 19,17 + 19,18 + 19 respectively. So the fraction can be written as 1 + 19 / 14,1 + 19 / 15,1 + 19 / 16,1 + 19 / 17,1 + 19 / 18. So the numerator is the same, and the larger the denominator is, the smaller the fraction is. So it is obvious who is bigger and who is smaller

It costs 1 / 3 of the total money to use a pen and 4 yuan to buy a story book. At this time, the ratio of the money spent to the rest is 5:4. What is the original money? How to write this question?