Please use the formula to solve the problem A research team observed and recorded the growth of three bacteria (labeled as 1, 2 and 3 respectively for the convenience of research) attached to the surface of the object. The three bacteria split into two in the first hour and produced new bacteria (labeled as 4, 5, 6, 7, 8 and 9 respectively), and then changed according to this rule every day, that is, each bacteria split into two, The formation of new bacteria (members of the research group use the figure as shown in the figure to record the image). Then how many hours will the bacteria labeled 120 appear?

Please use the formula to solve the problem A research team observed and recorded the growth of three bacteria (labeled as 1, 2 and 3 respectively for the convenience of research) attached to the surface of the object. The three bacteria split into two in the first hour and produced new bacteria (labeled as 4, 5, 6, 7, 8 and 9 respectively), and then changed according to this rule every day, that is, each bacteria split into two, The formation of new bacteria (members of the research group use the figure as shown in the figure to record the image). Then how many hours will the bacteria labeled 120 appear?

Initial state: 1, 2, 3 are 0 power of 3 * 2;
First hour: 4, 5 9 to the power of 3 * 2;
Second hour: 10, 11 A total of 3 * 2 to the second power;
Let 120 appear in the nth hour,
Then: 0 power of 3 * 2 + 1 power of 3 * 2 + The nth power of 3 * 2 is greater than or equal to 120
Calculate with the sum of equal ratio sequence, n = 5

Please consult the mathematics problem of grade one in junior high school
A store buys a batch of videos at the price of 16 yuan per 3 discs, and another one at the price of 21 yuan per 4 discs, which is twice the quantity of the previous batch. If the two kinds of videos are sold together at the price of K yuan per 3 boxes, 20% of the investment can be obtained, then the value of K is equal to?
When the average number of a, 2 and 14 is 8, and the average number of a, 10, B, 2, 4 and 0 is 5, then a2-b is?
In a2-b, 2 is the square!
Calculation: (a + 3A +...) +2003a)-(2a+4a+… +2004a)=?
It is the duty of every citizen to pay taxes according to law. For a period of time, according to the tax law of the people's Republic of China, citizens whose monthly wages and salaries do not exceed 800 yuan do not have to pay taxes, and those whose monthly wages and salaries exceed 800 yuan are taxed in sections according to the excess amount. See the following for details:
Tax rate of monthly tax amount (%)
Part a not exceeding 500 yuan
Over $500 to $2000 10
Over $2000 to $5000 15
… …
Master Zhang's total monthly income is 1250 yuan. As a result, he pays 22.5 yuan in tax every month?
Manager Li paid tax 45 yuan a month and asked for his salary this month
Thank you for your answers~

A store buys a batch of videos at the price of 16 yuan per 3 discs, and another one at the price of 21 yuan per 4 discs, which is twice the quantity of the previous batch. If the two kinds of videos are sold together at the price of K yuan per 3 boxes, 20% of the investment can be obtained, then the value of K is equal to?
Suppose that the first purchase is x boxes, that is, the second is 2x boxes. All goods are 3x
（X÷3×16＋2X÷4×21）×120%＝3X÷3×K
The solution is k = 19
When the average number of a, 2 and 14 is 8, and the average number of a, 10, B, 2, 4 and 0 is 5, then a2-b is?
a=8*3-(2+14)=8
b=5*6-(a+10+2+4+0)=6
a^2-b=8^2-6=58
Calculation: (a + 3A +...) +2003a)-(2a+4a+… +2004a)=?
=(a-2a)+(3a-4a)+...+(2003a-2004a)
=-A-A -... - A (1002)
=-1002a
It is the duty of every citizen to pay taxes according to law. For a period of time, according to the tax law of the people's Republic of China, citizens whose monthly wages and salaries do not exceed 800 yuan do not have to pay taxes, and those whose monthly wages and salaries exceed 800 yuan are taxed in sections according to the excess amount. See the following for details:
Tax rate of monthly tax amount (%)
Part a not exceeding 500 yuan
Over $500 to $2000 10
Over $2000 to $5000 15
… …
Master Zhang's total monthly income is 1250 yuan. As a result, he pays 22.5 yuan in tax every month?
Manager Li paid tax 45 yuan a month and asked for his salary this month
1) 1250-800 = 450 yuan, no more than 500 yuan, should be a% tax
450*a%=22.5
a=5
2)500*5%=25
(2000-500)*10%=150
The salary is between 500 and 2000 yuan
Suppose the salary is X
500*5%+[X-800-500]*10%=45
X=1500
That's 1500 yuan

Please give the answer, formula and a lot of homework in one hour
1) In the extracurricular activities, some students were divided into groups to participate in the activities. Originally, there were 8 students in each group. Later, they were reorganized into 12 students in each group. This reduced the number of students by 2 groups. How many students are there in total? (use the equation solution)
2) For a three digit number, the sum of the three digits is 17, the number on the hundred digit is 7 larger than the number on the ten digit number, and the number on the one digit is 2 / 3 (two-thirds) of the number on the hundred digit

1) Let's divide it into x groups
According to the meaning of the title: 8x = 12 (X-2)
2) Let 100 digits be X
2 / 3x + X-7 + x = 17
Come on, do it!

8. When calculating division, Xiao careless regards divisor 43 as 34, quotient 22 and remainder 32. What is the correct quotient and remainder?

The correct divisor should be: 34 * 22 + 32 = 780
So the correct division should be: 780 △ 43 = 18, the remainder is 6